Drum Teacher

Drum Teacher Guy

Phoenix, AZ - (718) 300-2007

Music History 

Written by D. Mark Agostinelli - the Drum Teacher Guy                    

  Music History by D. Mark Agostinelli

Music is the organized movement of sounds through a continuum of time.  Music plays a role in all societies, and it exists in a large number of styles, each characteristic of a geographical region or a historical era.


                II             Cultural Definitions
All known societies have music, but only a few languages have a specific word for it.  In Western culture, dictionaries usually define music as an art that is concerned with combining sounds, particularly pitches, to produce an artifact that has beauty or attractiveness, that expresses something, that follows some kind of internal logic and exhibits intelligible structure, and that requires special skill on the part of its creator.  Clearly, music is not easy to define, and yet most people recognize the concept of music and generally agree on whether or not a given sound is musical.

Indefinite border areas exist, however, between music and other sound phenomena such as speech, and the cultures of the world differ in their opinion of the musicality of various sounds.  Thus, simple tribal chants, a half-spoken style of singing, or a composition created by a computer program may or may not be accepted as music by members of a given society or subgroup.  Muslims, for example, do not consider the chanting of the Koran to be a kind of music, although the structure of the chant is similar to that of secular singing.  So someone that comes from New York City that is distant from the Muslim religion of Africa, may see the religious chant a being musical, rather than religious.  Yet someone from New York City, may hear this form of chanting, and find it to be extensively distant to comprehend, and to interpret into anything at all; is nearly impossible to the listener and bears no meaning at all.   The social context of sounds may determine whether or not they are regarded as music. Industrial noises, for instance, are not music except when presented as part of a concert of experimental music in an auditorium, with a listed composer.

Opinions also differ as to the origins and spiritual value of music. In some African cultures music is seen as something uniquely human; among some Native Americans it is thought to have originated as a way for spirits to communicate.  In Western culture music is regarded as inherently good, and sounds that are welcome are said to be "music to the ears." In some other cultures; for example; Islamic culture, it is of low value, associated with sin and evil, and attempts have been made to outlaw its practice.


                III            MUSIC AS A CULTURAL SYSTEM

Music has many uses, and in all societies certain events are inconceivable without it.  A proper consideration of music should involve the musical sound itself; but it should also deal with the concepts leading to its existence, with its particular forms and functions in each culture, and with the human behavior that produces the sound.

Somewhat comparable to having a language, each society may be said to have "a music," that is, a self-contained system within which musical communication takes place and that, like a language, must be learned to be understood.  Members of some societies participate in several musics; therefore, modern Native Americans take part in both traditional Native American music and mainstream American music.

Within each music, various strata may exist, distinguished by degree of learning (professional versus untrained musicians), level of society (the music of the elite versus that of the masses), patronage (court or church or public commercial establishments), and manner of dissemination (oral, notated, or through mass media).  

In the West and in the high cultures of Asia, it is possible to distinguish three basic strata; first, "art" or "classical" music, composed and performed by trained professionals originally under the patronage of courts and religious establishments; second, folk music, shared by the population at large, particularly its rural component, and transmitted orally; and, third, popular music, performed by professionals, disseminated through radio, television, records, film, and print, and consumed by the urban mass public.


                IV            Explain the sounds in Music
In the simplest terms music can be described as the combination of two elements that involve pitch and duration and that are usually called melody and rhythm.  The minimal unit of musical organization is the tone, that is, a sound with specific pitch and duration.  Music therefore consists of combinations of individual tones that appear successively (melody) or simultaneously (harmony) or, as in most Western music, both.


                A             Melody   - -   explain more

In any musical system, the creation of melody involves selecting tones from a prescribed set called a scale, which is actually a group of pitches separated by specific intervals (the distances in pitch between tones). Thus, the scale of 18th- and 19th-century Western music is the chromatic scale, represented by the piano keyboard with its 12 equidistant tones per octave; composers selected from these tones to produce all their music.  A lot of Western music is also based on diatonic scales, which have seven tones per octave, which are the white keys on the piano keyboard.  In the diatonic scales and in the pentatonic scales, those with five tones per octave, which are the black keys on the piano, are common in folk music, the tones are not equidistant.

Intervals can be measured in units called cents, 1200 per octave. The typical intervals of Western music are multiples of 100 cents, but in other musical cultures intervals of about 50, 150, and 240 cents, for example, are also found.  The human ear can distinguish intervals as small as 14 cents, but no interval that small seems to play a significant role in any musical system.

There more scales that I can talk about here.  Research Pentatonic scales

Hexatonic Scales

Amhemitonic scales

Equiheptitonic scales

Algerian Scales

Bantu Polyphony


B             Explain Rhythm  

The handling of time in music is expressed through concepts such as the lengths of notes and the interrelationships among them; relative degrees of emphasis on different tones; and, in particular, meter.

Most Western music is built on a structure of regularly recurring beats, that is, a metrical structure.  This structure may be explicit (as in the beating of the bass drum in popular music and marching bands), or it may be implied (often in symphonic or piano music). The three most common meters in Western music are units of four beats (with main stress on the first beat, secondary stress on the third beat); of three beats (stress on the first); and of six beats (primary stress on the first, secondary on the fourth).  There are also other structures that exists that are extremely complicated.  There are examples that have 5, 7, 8 counts and over 12 counts in a meter.  There are also genres from around the world that do not seem to have any structure at all and don’t follow a structured meter.   Such as, Indian classical music, and West African drum ensembles.  Some styles are so distant from a standard meter that it sounds incredibly sloppy, such as some genres in India and the Middle East, and Jewish, Islamic, and Buddhist liturgical chant.


                C             Other Elements


The organization given to simultaneously produced pitches is also of great importance. Two or more voices or instruments performing together may be perceived as producing independent although related melodies.  This is what we call counterpoint. 

Timbre, or sound quality, is the musical element that accounts for the differences in the characteristic sounds of musical instruments.  

Singers have a variety of timbres as well, each affected by such features as vocal tension, rasp, nasality, amount of accentuation, and slurring of pitch from one tone to the next.

One major characteristic of music everywhere is its transposability.  A tune can be performed at various pitch levels and will be recognized as long as the interval relationships among the tones remain constant.

These elements of music are used to organize pieces extending from simple melodies using a scale of three tones and lasting only ten seconds (as in the simplest tribal musics) to highly complex works such as operas and symphonies.  The organization of music normally involves the presentation of basic material that may then be repeated precisely or with changes also known as variations, may alternate with other materials, or may proceed continually to present new material. Composers in all societies, often unconsciously, strike a balance between unity and variety, and all pieces of music contain a certain amount of repetition, whether of individual tones, short groups of tones which are called motives, or longer units such as melodies or chord sequences which are often called themes.


                D             Instruments

Through my time of studying music and listening to styles from all over the world.  I have noticed that all societies have vocal music; and with few exceptions.  Also, they all have instruments.  Among the simplest of instruments are sticks that are struck together; notched sticks that are scraped, rattles, and body parts; such as femurs and bones, or hands slapping a thigh or clapping to produce sound.  Some of the simplest Instruments can make the greatest sounds and create some the greatest music.  Such simple instruments are found in many tribal cultures. Also these simple tribal instruments are used all over the world as baby toys or in archaic rituals.  Certain highly complex instruments exhibit flexibility not only in pitch but also in timbre.  The piano produces the chromatic scale from the lowest to the highest pitch used in the Western system and responds, in quality of sound, to wide variation in touch.  On the organ, each keyboard can be connected at will to a large number and combination of pipes, thereby making available a variety of tone colors.  On the Indian sitar, one plucked string is used for melody, other plucked strings serve as drones, while still others produce fainter sounds through sympathetic vibration.  Modern technology has utilized electronic principles to create a number of instruments that have almost infinite flexibility.

There are many different types of Instruments that exist in the world.  Classification systems had to be developed.  There are countless classification categories to explain the different types of instruments that exist.  However here is a small list of examples.  Examples of such classifications are:

1. Idiophones, in which the main vibrating units are the resonant bodies of the instruments themselves (for example, rattles and xylophones);

2. Membranophone, which have vibrating skins (drums);

3. Chordophones, which have vibrating strings (violins, guitars, pianos);

4. Aerophones, which produce vibrating bodies of air (clarinets, reed and pipe organs, harmonicas); and

5.  Electrophones, in which electronic circuits produce sound (electronic organs, sound synthesizers).


                V             THE CREATION OF MUSIC
Music is created by individuals, using a traditional vocabulary of musical elements. In composition (the principal creative act in music) something that is considered new is produced by combining the musical elements that a given society recognizes as a system.  Innovation as a criterion of good composing is important in Western culture, less so in certain other societies. In Western music, composition is normally carried out with the help of notation; but in much popular music, and particularly in folk, tribal, and most non-Western cultures, composition is done in the mind of the composer, who may sing or use an instrument as an aid. Creative acts in music also include improvisation, or the creation of new music in the course of performance. Improvisation usually takes place on the basis of some previously determined structure, such as a tone or a group of chords; or it occurs within a set of traditional rules, as in the ragas of India or the maqams of the Middle East. Performance, which involves a musician's personal interpretation of a previously composed piece, has smaller scope for innovation. It may, however, be viewed as part of a continuum with composing and improvising.

The normal method of retaining music and transmitting it is oral or, more properly, aural— most of the world's music is learned by hearing. The complex system of musical notation used in Western music is in effect a graph, indicating principally movement in pitch and time, with only limited capability to regulate more subtle elements such as timbre. Both Western and Asian cultures possess other notation systems, giving letter names of notes, indicating hand positions, or charting the approximate contour of melodic movement.

                VI            THE SOCIAL ROLE OF MUSIC
Music everywhere is used to accompany other activities. It is, for example, universally associated with dance. Although words are not found in singing everywhere, the association of music and poetry is so close that language and music are widely believed to have had a common origin in early human history.

                A Function of Music
Music is a major component in religious services, secular rituals, theater, and entertainment of all sorts. In many societies it is also an activity carried on for its own sake. In American society in the late 20th century, for example, one main use of music involves listening at concerts or to radio or records (music for its own sake); another involves the provision of music as a suitable background for unrelated activities such as study or shopping (music as an adjunct to something else). In many societies music serves as the chief entertainment at royal courts. Everywhere, musicians sometimes perform for their own diversion; in some societies, however, this private use of music has been formalized—in southern Africa, for example, special genres and styles are reserved for musicians' performances for their personal entertainment.

The most ubiquitous use of music, however, is as a part of religious ritual. In some tribal societies, music appears to serve as a special form of communication with supernatural beings, and its prominent use in modern Christian and Jewish services may be a remnant of just such an original purpose. Another, less obvious, function of music is social integration. For most social groups, music can serve as a powerful symbol. Members of most societies share keen feelings as to what kind of music "belongs." Indeed, some minorities (including, in the U.S., black Americans and Euro-American ethnic groups) use music as a major symbol of group identity.

Music may serve as a symbol in other ways, as well. It can represent nonmusical ideas or events (as in the symphonic poems of the German composer Richard Strauss), and it can underscore ideas that are verbally presented in operas (notably those of the German composer Richard Wagner), in film and television drama, and often in songs. It also symbolizes military, patriotic, and funerary moods and events. In a more general sense, music may express the central social values of a society. Thus, the hierarchical caste system of India is symbolized in the hierarchy of performers in an ensemble. The avoidance of voice blending in a Plains peoples singing group reflects the value placed on individualism. In Western music the interrelationship of conductor and orchestra symbolizes the need, in a modern industrial society, for strongly coordinated cooperation among various kinds of specialists.

                B             The Musician In most of the world's societies, musicianship requires talent, special knowledge or training, and effort, and the view is widespread that a successful musical work or performance is difficult to achieve. There is no evidence that superior musical abilities arise in one society or race as opposed to another; rather, variations in achievement are the result of differences in technology, in the degree of specialization of musicians, and in the value placed on music. Individual talent, however, is recognized among most peoples, and the musical specialist exists everywhere: as a true professional in the West, India, the Far East, and Africa; as an informal leader and singer in folk cultures; and as someone who also has supernatural power in tribal societies. But if music is regarded as indispensable everywhere, the musician has rarely enjoyed great prestige. In certain early societies in Europe and America, for example, musicians were regarded as undesirable social deviants; this remains the case in the present-day Middle East. In many societies music is relegated to outsiders—foreigners or members of religious and ethnic minorities. Many modern social systems, including those in the West, inordinately reward the outstanding "star" performer but pay little attention to the average musician. Nevertheless, musicianship in most parts of the world requires long periods of concentrated study, extending in the case of European and Indian virtuosos to some 20 years.

                VII          MUSICAL REGIONS
Each culture has its own music, and the classical, folk, and popular traditions of a region are usually closely related and easily recognized as part of one system. The peoples of the world can be grouped musically into several large areas, each with its characteristic musical dialect. These areas include Europe and the West; the Middle East with North Africa; Central Asia and the Indian subcontinent; Southeast Asia and Indonesia; Oceania; China, Korea, and Japan; and the Americas (Native American cultures). All coincide roughly with areas determined by cultural and historical relationship, but, surprisingly, they do not correspond well with areas determined by language relationships.

The history of Western music—the one most easily documented because of Western musical notation—is conveniently divided into eras of relative stability separated by short periods of more dramatic change. The periods conventionally accepted are the middle Ages (to c. 1450), the Renaissance (1450-1600), the baroque era (1600-1750), the classical era (1750-1820), the romantic era (1820-1920), and the modern period. Other cultures, less well documented, likewise have experienced change and development (not necessarily always in the direction of greater complexity), so that the simplest tribal musics also have their histories. In the 20th century, however, rapid travel and mass communication have led to a great decrease in the musical diversity of the world.[1]


Musical Form, the orderly arrangement of musical elements in time. Because music takes place in time, its form unfolds in time. Repetition and contrast are the two fundamental characteristics of musical form, even in simple pieces such as "Mary Had a Little Lamb" (the two halves of which begin identically but end differently).

In music, repetition arouses in the listener both a remembrance of what was heard and an anticipation of what is to come. This is true both of recognizable details and also of subtler patterns that are only subliminally recognized. Also, every musical system has conventions that are explicitly or implicitly understood by listeners, and these conventions have an effect on the interpretation of what is heard, remembered, and anticipated.

                II             COMMON FORMAL PATTERNS
Musical form can be analyzed from several levels of detail. Overall formal patterns are often described in terms of the major sections within a piece. For example, the melody of "America" has two contrasting sections (one beginning "My country, 'tis of thee ..." and the other beginning "Land of the pilgrims' pride ..."); this form can be represented by the letters AB. Another song, "Twinkle, Twinkle, Little Star," has three sections; the first and last ("Twinkle, twinkle ...," at the beginning and end) are the same, but they contrast with the middle section ("Up above the world so high ..."). This form can be represented as ABA.

                A             Sectional Patterns  
Sections of a composition can be related to one another in four ways, the first three of which utilize the principle of repetition: (1) exact repetition; (2) variation (repetition with some aspect changed—elaborations added to the melody or alterations of the harmony or rhythm); (3) development (components of the original section, such as a melodic fragment or a rhythm, are taken apart and recombined in new ways to create a new section); and (4) contrast (the new section is markedly different from the preceding one). These relationships provide the basis for musical forms that are found either universally or within particular cultures and historical periods.

                A1           Repetition and Variation
Simplest among formal patterns are the repetitive formulas of the psalm tones of Gregorian chant and of various tribal chants. In strophic form, the music is repeated for each stanza of a song; in strophic variation, the music is varied with each stanza. In instrumental music this latter approach produces the variation form, as in Wolfgang Amadeus Mozart's Variations on a Nursery Tune, K. 265 (the tune is that of "Twinkle, Twinkle, and Little Star"). Variations need not be based on an entire melody, however; often a series of chords or a short motive or phrase provides the unifying element. Most jazz improvisations, for instance, are variations created to fit the harmonies of a given melody. In non-Western melody types, such as the raga of Indian music and the maqam of Arab music, variations take the form of improvisations on the motives and patterns associated with the particular raga or maqam.

                A2           Sectional Contrast
Many musical forms are based on contrast as well as repetition of sections. Binary form consists of two contrasting sections that function as statement and counterstatement. The pattern may be a simple AB, as in "America," or it may be complicated by repetition, as in the medieval ballade (AAB), or by variation, as in the tune "Greensleeves" (AA’BB’, with A’ meaning "variation of A"). In the binary form found in much music of the baroque era (circa 1600-c. 1750) the pattern involves change of key: Section A begins in one key and ends in another; section B begins in the new key and ends in the original key; each section is repeated, giving the pattern AA BB.

Songs frequently take the form ABA (ternary or three-part form, often called song form). In the da capo aria of 17th- and 18th-century opera, the pattern was ABA’, the singer being expected to improvise variations when the A section was repeated. In the late 18th and 19th centuries, the minuet or scherzo movement of a sonata, symphony, or other multimovement work constituted an ABA form: an initial minuet or scherzo, followed by a contrasting one (called the trio), followed by repetition of the initial one. (Such a pattern also provides an example of hierarchical levels of form, for within the ABA format, each minuet or scherzo is itself built on a two-part scheme.)

One variant of ternary form is the AABA form common in 20th-century popular songs such as "Over the Rainbow" (the B section is called the bridge). The song "I Want to Hold Your Hand," by John Lennon and Paul McCartney, with its form AA BA BA’, illustrates how composers expand such basic patterns.

The alteration of contrasting sections is expanded in forms such as the rondo and in the ritornello form developed in the concerto. In the latter, the ritornello section recurs periodically. Rondos, common in 18th- and 19th-century music, are cast in various patterns such as ABACA, ABACADA, and ABACABA.


                A3           Development and Sonata Form
the form that dominated music of the classical period (circa 1750-c. 1820) was the sonata-allegro or sonata form, so called because of its use in instrumental sonatas. Based on the principle of contrast of key, the sonata form developed out of the baroque binary form that involved change of key (some theorists, however, view sonata form as a complex ABA pattern). The pattern of sonata form is exposition (material beginning in an initial key and moving into a new key), followed by development (fragmented exposition material passed through many keys) that leads into recapitulation (restatement of the exposition material, but usually all in the initial key). The sonata principle of fragmentation and development in many keys permeated other formal patterns of the same era.


                B             Other Organizational Approaches  


The term through-composed has been applied to pieces having no clear pattern of repeated sections (such as the 16th-century fantasia, which has sections of contrasting texture but rarely any obvious repetitions). Perhaps the simplest examples are folk songs such as "Barbara Allan," in which the four phrases have the pattern ABCD. (In such songs, the four phrases are often unified by rhythmic motives, a relationship among final notes, and other devices.)

In its narrowest sense, the term through-composed refers to 19th-century song settings in which each stanza of text is given its own new music; an example is "Erlkönig" (Erl King) by the Austrian composer Franz Schubert. Much instrumental music, however, is also through-composed; examples from the 19th century include many nocturnes, romances, and other character pieces. In a through-composed piece, the structure arises from such elements as the composer's use of subtle relationships among motives, similarities and contrasts of texture, and relationships of key and harmony.

Between about 1200 and about 1750, counterpoint (the interweaving of melodies), especially in the form of melodic imitation, was a prominent technique for creating musical form. (The simplest example of melodic imitation is the round.) Imitation was the means for creating unity in forms such as the motet and fugue as well as in masses. Other sources of musical coherence were mode (a scale with certain notes serving as focal points); the composer's use of harmony; and the use of a cantus firmus (a recurring plainchant or secular melody, nearly always disguised by elongating its notes and usually buried in the contrapuntal texture.

In the 19th century a nonmusical program (a sketchy or detailed outline of the events or emotions that the music is intended to portray) was a frequent source of structure; the details of the program guided the composer's manipulation of purely musical elements.


                C             Multimovement Forms  

Instrumental and vocal music is often composed in forms consisting of several movements (independent or almost independent sections, each with its own form such as sonata form or rondo or variations). Instrumental examples include the baroque suite and the classical symphony, sonata, and string quartet. Composers unify such works by relating their keys and sometimes their melodic material; a work with systematic melodic relationships between movements (such as a cantus firmus mass, or Schubert's "Wanderer Fantasy," op. 15) is said to be cyclic. Variety is usually provided by changes in tempo from one movement to another; a common pattern is slow-fast-slow-fast. In masses, song cycles, operas, cantatas, oratorios, and similar vocal works, the text provides an additional unifying element.


                D             Form and Content  

Conventional musical forms such as the rondo, fugue, and sonata are defined by the particular patterns that are imposed on melody, harmony, and other musical elements.

The explicit codification of musical forms arose in large part during the 19th century, an era in Western music history in which themes (melodies) and their transformations dominated musical thought. As a result, many forms were viewed as molds into which the themes of an individual composition were poured. From this perspective, pieces that differed from the "textbook" form in various details were viewed as creative license. In the 20th century this viewpoint was challenged by many critics, beginning perhaps with the English critic Donald Francis Tovey, who pointed out that few compositions by the great masters adhere strictly to a stereotyped form. Today, form in the sense of overall pattern is usually viewed as inseparable from content—the details of rhythm, themes, and textures and all other aspects of a composition. Specific forms (such as a sonata or fugue) are now understood as processes or principles according to which individual pieces will vary, depending on their content. Thus, a fugue is viewed as a type of composition using melodic imitation, whereas earlier analysts saw it as a regular sequence in which one kind of imitation followed another predictably. Similarly, a sonata-form movement is heard as a certain kind of structure created by the contrast of keys and the manipulation of themes and motives, whereas earlier theorists usually described it as a conventional sequence of themes, transitions, and developments. This conception of form as unified with content is also useful in understanding non-Western musical forms.


                III            PRINCIPLES AND ELEMENTS  


In the most fundamental sense, musical form goes beyond sectional patterns and is created by the composer's organization of melody, rhythm, harmony, and other elements. Such organization can exist on several levels, from small details within individual phrases to large-scale plans of organization—basic formal patterns that have unity, variety, and symmetry.


                A             Melody  


The repetition and recombination of fleetingly recognizable melodic motives and fragments, as well as the clear restatement of longer patterns, help create unity and coherence while also ensuring variety. Two or more melodies in a piece may be related because they share certain motives; the sharing of motives may or may not be obvious. Sections of melody may differ in contour—the pitch changing in stepwise versus leaping motion, rising versus falling direction. Such variety provides small-scale contrast and may also highlight larger divisions within a composition.


                B             Time and Rhythm  


Another element that influences musical form is the relation of units of time to one another, whether the relation of long and short notes in a rhythmic motive, or the relative lengths of movements in a symphony. Large underlying patterns may also provide structure. Medieval European composers sometimes repeated complex, overlapping melodic and rhythmic patterns throughout a piece; this procedure, called isorhythm, provides coherence even though the patterns may not be readily apparent to the listener. At a more detailed level, short rhythmic motives may recur in different melodic and harmonic contexts, thus contributing to the unity of a work. In some Eastern music, long, conventional rhythmic cycles such as the iqa of Arab music and the tala of Indian music also provide structure and are recognized with delight by knowledgeable listeners.


                C             Harmony  

Another resource for form is harmony. Consonant harmonies are those that sound stable; dissonant harmonies sound unstable or seem to clash, and they tend to be resolved into consonant harmonies. Composers exploit the tension between consonance and dissonance to establish a sense of beginning and end, of movement and repose. Between about 1650 and about 1900 the classical Western system of tonality regulated harmonies according to a complex set of conventions. Tonality provided a strong means of organization, because all notes and chords were related in a specified way (whether strongly or weakly) to the tonic—the focal note (keynote), chord, and key. In the 20th century composers such as the German Paul Hindemith and the Hungarian Béla Bartók developed nontraditional methods of creating music centered around a tonic note. These included repetition of critical notes, symmetrical movement above and below the tonic, and new approaches to dissonance.


                D             Serialism
Other composers followed the twelve-tone system of the Austrian composer Arnold Schoenberg. Usually abandoning tonality altogether, they derived their harmonies and melodies from an arbitrary series of the twelve notes of the chromatic scale (the notes of the black and white keys of the piano). Called serialism, such organization according to an underlying series has been extended to rhythms, timbres (tone colors), dynamics (loud and soft), and other musical elements.


                E              Other Resources
Other aspects of music that can be manipulated to create musical organization are texture (dense or sparse, chordal or contrapuntal) and register (high or low pitch areas). In different ways, for example, the Russian-born composer Igor Stravinsky and the French-American composer Edgard Varèse created musical structures by manipulating textures and blocks of sound. Complex mathematical relationships have been used by the Greek composer Yannis Xenakis and others as a basis for musical form.


                                Musical Instruments


Musical Instruments, tools used to expand the limited scope of musical sounds—such as clapping, stamping, whistling, humming, and singing—that can be produced by a person's unaided body. Throughout the world, instruments vary greatly in purpose and design, from natural, uncrafted objects to complicated products of industrial technology. Although sirens, automobile parts, and radios have been employed in avant-garde compositions, this article mainly concerns those specialized implements intended for performing the world's conventional folk, popular, and classical music.


                II             THE PRODUCTION OF SOUND
Sound arises from vibration transmitted by waves to the ear. Incoherent, violent vibration is normally interpreted as noise, whereas regular, moderate motion produces tones that can be pleasing. The faster the vibration, the higher the pitch that is perceived. Some pipe organs encompass the full audible range of pitch, approximately 16 Hz (hertz, or cycles per second) to 20,000 Hz, or more than ten octaves, but most instruments have a much more limited compass; indeed, many play only a single note or have no identifiable pitch at all.

The greater the amplitude or power of audio waves, the louder their sound, which in some electronically amplified music can reach a painful, ear-damaging intensity. The timbre, or tone color, of the sound is influenced by the presence and relative strength of overtones, or harmonics, in the sound wave. The perception of timbre, however, is also affected by the duration and location of the sound, and by its envelope, or its characteristics of attack (onset) and decay (which may, for example, be abrupt or gradual, or—especially in attack—may involve transient harmonics). The sounds of musical instruments are caused and modified by three components: (1) the essential vibrating substance (such as a violin string), set into motion by bowing, blowing, striking, or some other method; (2) the connected reflector, amplifier, or resonator (soundboard, tube, box, or vessel); and (3) associated sound-altering devices, among them keys, valves, frets, and mutes.


                III            SYSTEMS OF CLASSIFICATION  

Instruments can be classified in different ways—for example, by their primary materials (metal, wood, earthenware, skin, and so forth, an arrangement followed in East Asia); their social status and appropriate setting (church, military, parlor); or their musical role (rhythmic, melodic, chordal, drone). Since the 2nd century BC, Western audiences have conventionally distinguished among winds, strings, and percussion. This exclusive division, however, does not accommodate instruments such as the piano, which employs both strings and a percussion mechanism; or the aeolian harp, a zither the strings of which are vibrated by the wind. Nor is the familiar distinction of brasses from woodwinds quite logical: Saxophones and orchestral flutes are metal woodwinds, whereas early "brasses" were often made of animal horn (the shofar), wood (the serpent, a bass instrument), or even ivory (the cornetto, a small Renaissance horn).

A comprehensive classification based on acoustical principles was devised in the 19th century. Instrument families are defined in terms of what vibrates to produce the sound. These families are the idiophones—solid, intrinsically sonorous objects; membranophones—taut membranes; aerophones—enclosed or free masses of air; and chordophones—stretched strings. A fifth family, electrophones—oscillating electronic circuits—originated recently.


                IV            IDIOPHONES  

The largest, most varied and widespread, and probably the oldest instrument family consists of idiophones. Known at least since the Stone Age, idiophones range in complexity from hollowed logs (slit-drums) of indefinite or tuned pitch that are used rhythmically, often to send signals, to precisely tuned cast-bronze bells that, combined in a carillon, form the most massive and expensive of instruments. Bells vibrate at their rim, whereas gongs—perhaps invented in Southeast Asia by Bronze Age metal smiths—vibrate at their center. The so-called steel drum or piano pan is a modern Trinidadian gong that produces more than one pitch from its segmented surface.
These examples are known as percussion idiophones because they are all struck with beaters. Such instruments are often played in sets. The xylophone is a set of tuned hardwood bars. In Indonesian music, the saron is a metallophone, made up of bronze bars; the bonang, a set of small tuned gongs. The celesta is a metallophone with a piano like keyboard. A piano hammer action also strikes the glass bars of the glasschord, a 19th-century English crystallophone. The oldest existing sets of tuned-bar idiophones, excavated in East Asia, are lithophones, made of stone; lithophones were also made in 19th-century England.

Concussion idiophones are struck together, usually in pairs. Turkish-style brass cymbals and Spanish wooden castanets are the most familiar types, but ivory and bone clappers were common in ancient Egypt. Egyptian worshipers also used the sistrum, a rattle with metal rings fitted loosely on rods. Rattles are normally shaken rather than struck. They include vessel types, with loose rattling objects enclosed in a container; strung rattles, with small, hard objects tied together or to a handle; and frame rattles, such as the sistrum and the Javanese angklung (tuned bamboo tubes sliding within a framework). The jingle, or pellet, bell is a metal vessel rattle, not a true bell.

Other idiophones may be scraped, as is the washboard played in old-time jug bands; or they can be rubbed with a bow (as in a nail violin) or with the fingers. Moistened fingers rub the rims of musical glasses, tuned by partial filling with water.  Plucked idiophones include the rotating ratchet used as a holiday noisemaker; the African mbira or thumb piano, the many metal or cane tongues which can be individually tuned; and the music box, with its "comb" of flexible steel teeth that are plucked by pins which are on a rotating cylinder.


                V             MEMBRANOPHONES  

All true drums belong to the membranophone. A drum has one or two heads of skin or plastic stretched over a resonator or over a narrow frame. Kettledrums, having a single head over a bowl-shaped resonator, are produced in all sizes. Orchestral kettledrums are tuned by means of hand screws or pedals, whereas some non-Western types are tuned with paste or heat applied to the head, or by manipulating the lacing which attaches to the head or heads. Hard and soft beaters offer tonal variety. In India the technique of playing small kettledrums (the baya in the pair called tabla) with the hands is a subtle art.

Cylindrical drums, usually unpitched, vary in size from huge basses drawn on wagons in parades, to shallow, waist-slung drums equipped with snares that intensify the sound. In parts of Africa and the Pacific Islands sacred drums are taboo to the uninitiated; their wood bodies are elaborately carved and decorated, and revered drums occupy huts to which votive offerings are brought. Slender, elongated drums with reptile-skin heads glued on with human blood accompany male ritual dances in New Guinea.

Some Native Americans accompany tribal dances and chants on broad, shallow drums beaten by several players at once. A light hand-held frame drum is played by Eskimo shamans; it resembles Asian shamans' drums. The tambourine is a frame drum that usually has rattles attached to the frame; it is both struck and shaken and is sometimes rubbed.

The rommelpot is a Flemish friction drum played as a toy; rubbing a stick or string protruding through its head causes the head to vibrate. A more important membranophone is the mirliton. Not actually an instrument in its own right, but rather a tone modifier, the mirliton is a thin membrane attached over a hole in a resonator, adding a buzzing quality to the sound. One popular mirliton, the kazoo, disguises the voice. Other mirlitons enrich the tone of instruments as diverse as African xylophones, drums, and Chinese flutes.


                VI            AEROPHONES  

Among aerophones, several different methods are used to set the air in vibration.


                A             Flutes  

In flutes a wind stream impinges on an edge, setting up eddies in an enclosed body of air. The wind may come from the player's lungs, a bellows or squeezed windbag, or a mechanical fan. If the resonator enclosing the air is a tube, its length determines the pitch; usually, tone holes in the tube wall are opened or closed to change the sounding length and, hence, the pitch.

In the orchestral flute the lips direct breath against the edge of a mouth hole in the tube wall; such flutes are called transverse, or side blown. The Japanese shakuhachi is blown against the sharpened rim of one end. A panpipe is also end blown; each of its pipes gives a different note, according to its length. Some end-blown flutes are blown through one nostril; such "nose flutes" are often considered magical.

In whistles and recorders an internal duct aims the breath against the edge of a hole in the wall; the flue pipes on an organ thus operate like one-note whistles. Some Native American flutes have a duct on the outside of the tube, a system unknown otherwise. The ocarina, a popular ducted flute invented in Italy (about 1860), has a globular resonator rather than a tubular one, giving it a hollow, dark tone. In general, the shape of an aerophone's resonator has a more critical effect on timbre than does its material, because the resonator walls vibrate little, compared to the air within.


                B             Single and Double Reeds  

Among reed-vibrated aerophones, the clarinet, saxophone, and their relatives employ a single broad reed of springy cane fastened at one end over a hole in a mouthpiece. The reed responds to breath pressure by beating against the hole many times per second, allowing puffs of wind into the tube to vibrate the enclosed air. The brass-reed pipes of an organ are of this type.

The oboe, bassoon, shawm, and other double-reed instruments produce sound when two slender blades of cane pinch together rapidly, thus interrupting the wind stream passing between them into the resonator. Whereas clarinets have a more-or-less cylindrical tube, oboes have a conical pipe; the different internal shapes foster distinctive patterns of harmonics that give these instruments their characteristic timbres.


                C             Free Reeds and Other Instruments  

In free-reed aerophones such as the mouth organ, or harmonica, the accordion, and reed organs (harmonium, melodeon), many brass reeds of graduated size produce the sounds. Under wind pressure each reed vibrates back and forth through a close-fitting aperture. Because the length and shape of each free reed determines its pitch and timbre, no resonator is required; the reed vibrates air in the atmosphere. All Western free-reed instruments evolved from the Oriental mouth organ with multiple pipes (such as the Chinese sheng and the Japanese sho), introduced into Europe in the 18th century.

The bull-roarer, a tapered wood blade whirled around on a string, also vibrates the atmosphere directly without benefit of a resonator. Its unpitched rumble sounds powerful and mysterious. The Jew’s harp has a twangy tone that arises when the stiff metal or cane reed is plucked in front of the mouth and vibrates the air within.


                D             Lip-Vibrated Instruments  

In the orchestral brasses and other lip-vibrated aerophones, the player's lips buzz against a cup- or funnel-shaped mouthpiece inserted in a conical or cylindrical tube. Broadly speaking, conical, wide-bore tubes characterize horns, whereas relatively cylindrical, narrow-bore tubes define trumpets. The sounding length of the tube can be altered by means of fingered or keyed tone holes; by valves that open and close sections of tubing; or by a sliding telescopic section of tubing, as on the trombone. The cornetto and serpent, for example, have finger holes much like those of a recorder. The keyed trumpet and keyed bugle became obsolete only when valves were widely adopted for brasses in the 19th century.
In many aerophones, overblowing (drastically increasing the wind pressure) forces higher harmonics to supersede the fundamental pitch. A bugler, whose instrument is a tube of constant length, can thus play tunes by overblowing to produce various harmonics. Brasses of unvariable sounding length are called natural; they are limited to the notes of the harmonic series. As composers since the 1500s gradually made greater demands on trumpets and horns (which were originally outdoor signal instruments), instrument makers invented the key and valve mechanisms that enable the instruments to produce fully chromatic scales. Woodwinds, similarly, were fitted with complex key mechanisms. Such structural changes, however, necessarily affected the timbre; modern brasses, as well as keyed woodwinds, sound noticeably different from those of the early 19th century and before.


                VII          CHORDOPHONES  

Being of more recent origin than idiophones, drums, and winds, the chordophones are not universally distributed; they were virtually unknown in pre-Columbian America (before the 16th century). Chordophones differ widely in structure, but are all thought to have evolved from the archaic musical bow, which resembles a hunting bow and is played like a jew's harp. Because the sound of a vibrating string alone is extremely quiet, strings are almost always coupled to a resonator.


                A             Zithers  

In the zither group, the strings stretch side by side over a soundboard or sound box, and, with the exception of the Chinese qin (ch'in), communicate their vibrations to either by means of one or more bridges. The Japanese koto has movable bridges, one for each string. This revered zither, like the bridgeless qin, has an extensive classical repertoire. The Appalachian dulcimer (not the same as the hammered dulcimer) evolved in the late 19th century from northern European fretted zithers brought to America by immigrants. These folk zithers have melody strings passing over a fretted fingerboard, in addition to unfretted accompaniment strings.


                B             Keyboard Chordophones  

Two zither-family instruments, the hammered dulcimer and the medieval psaltery, are ancestors of keyboard chordophones such as the piano, clavichord, and harpsichord. The last two instruments were invented in the late middle Ages (the late 14th and early 15th centuries) in conjunction with the emergence of multipart music. The piano, with its wider dynamic range, appeared about 1700. It largely replaced the hammered dulcimer in urban domestic use, and by 1800 it had superseded the quieter clavichord and harpsichord. The hurdy-gurdy, which is a fiddle with a keyboard of limited compass, has both melody and drone strings, sounded by a rotating circular "bow" of wood. It resembles the Swedish nyckelharpa, a keyed fiddle played with a conventional bow.


                C             Harps and Lyres  

Unlike zithers, which may be plucked, bowed, struck, or wind-sounded (the aeolian harp), true harps are almost exclusively plucked. Their many strings fasten directly into the resonator; no bridge is necessary. The frame of European harps consists of a sound box, a neck (called the harmonic curve), and a forepillar, roughly forming a triangle. Ancestral, non-Western harps such as the Myanmar saung lack the reinforcing forepillar; their angled or arched necks, therefore, cannot withstand extreme string tension. The African pluriarc has a separate neck for each string.

A modern concert harp has a pedal mechanism that alters the pitch of each string by one or two semitones, thereby producing a full chromatic compass although having only seven strings per octave. Simpler pedal and manual devices offered chromatic notes in 18th-century harps, but earlier chromatic harps (notably the Welsh telyn) had two or three rows of strings, each chromatic note having its own string. Although most European harps are strung with gut or synthetic cords, the massive Irish harp traditionally is wire strung. Once favored to accompany bards, the Irish harp became a patriotic symbol when its use was outlawed by English authorities.
On lyres, the strings are anchored to a crossbar supported by two arms that extend from a box- or bowl-shaped resonator; they are coupled to the resonator by a bridge. Lyres are rare today outside Ethiopia; however, the Greek ancestor of the Ethiopian lyre was a popular instrument. The kithara was a large, wood-bodied concert lyre of ancient Greece; derivatives of its name were given to unrelated instruments such as the cittern and guitar.


                D             Plucked and Bowed Lutes  

The European lute is the namesake of a group of bowed and plucked instruments. Their strings pass along a neck that extends from the resonator, and a bridge couples the strings to the resonator. The neck may be a short elongation of the body, as in the Chinese pipa; or it may be a separate element fastened to or piercing the body. Frequently, the neck incorporates a fingerboard (which may be fretted), against which the strings can be pressed to alter their sounding length.

Plucked lutes include the banjo and guitar as well as the pear-shaped Arabic 'ud, from which the name of the European lute is derived. The technique of bowing is not as old as that of plucking, and fiddles, or bowed lutes (such as the violin and viol) arrived in Europe from Asia only in the middle Ages. Early European bowed lutes are hardly distinguishable from plucked ones. Evidence of medieval types is limited to fragmentary remains, literary descriptions, and pictures—practically no complete examples survive, due to the instruments' fragility. Comparison with similar-looking modern folk instruments suggests that the latter have changed little since the Middle Ages.

The viola, which evolved from unstandardized medieval fiddles, is first depicted in early 16th-century pictures. Like most other instruments of the Renaissance, it was built in a range of sizes that, together, made up a consort. Small violas (violins), large ones held between the knees (violoncellos; Cello), and even larger ones played standing up (violones) were the specialty of Italian artisans such as the Amati family and Antonio Stradivari. The pochette or kit, a miniature violin-type instrument played by dancing masters, often had a one-piece body and neck carved from a block of wood; it thus resembled the medieval rebec, the name and shape of which were in turn derived from the Middle Eastern rabab.

The violin and its relatives—at first associated with country dance music and considered inferior to the quieter, more sedate viola da gamba (viol)—became supreme during the 18th century (and earlier in Italy) because viols were less well suited to the highly dramatic style of late baroque and classical music. When the intimate idiom of the classical era gave way to the 19th-century romantic style, violins and most other orchestral instruments were modified to increase their compass and dynamic range. Loudness and brilliance became necessary because of the introduction of large concert halls and the virtuosic demands of romantic composers and performers.

Among the interesting hybrid chordophones are the baryton, a viol equipped with additional thumb-plucked wire strings; and the arpeggione, a cello-sized bowed guitar briefly popular in the 1830s. The viola d'amore, still called for by a few 20th-century composers, has unfingered strings that vibrate sympathetically beneath the bowed ones, giving an especially warm tone. Sympathetic strings are found also in many Asian chordophones, particularly in India, where the gourd-bodied sitar is a favorite vehicle for classical improvisation. West African plucked instruments such as the kora (harp-lute) and the muet (harp-zither) combine features of harps, lutes, and zithers.


                VIII         ELECTROPHONES  

Just as mechanical invention served European music when the fully developed keyboard (a device uniquely associated with Western technology) arose in the late middle Ages, so electrical engineers have offered 20th-century musicians an innovative means of producing and controlling sounds. The telharmonium, an electrophone created by the American inventor Thaddeus Cahill at the turn of the century, produced novel tones with a collection of equipment that included rotary generators and telephone receivers. The theremin, a compact apparatus invented by the Russian physicist Leon Theremin, was fashionable in the late 1920s and 1930s, although it could play only a single melodic line. Electronic organs have mainly influenced popular music, but since the mid-1950s synthesizers have become important tools of composers in many idioms.  Since the 1930s electronic amplification has tremendously increased the impact and altered the technique of popular singers and instrumentalists. In the electric guitar such amplification replaced the sound box and stimulated new musical effects. Except in the distortions and manipulations of sound used in rock music, however, amplification, like broadcasting and recording, serves chiefly to disseminate music rather than to create it. The long-term implications of electronic sound production cannot yet be predicted.


Musical Notation, system of written symbols that represent musical sounds. The primary requirement of any notation is that it be suited to the music it represents.

                II             WESTERN STAFF NOTATION  

The standard notation of Western music is a staff notation. Its basis is a staff (or stave) of five lines. Each line and the space between lines represents a different pitch. A tone of a given pitch is represented by a sign called a note, placed on a line or in a space. A clef, positioned at the beginning of every staff, indicates the pitch assigned to one of the lines, from which the others are reckoned. Since the octave contains 12 pitches a semitone (that is, a half-step) apart, and since the staff, for historical reasons, has lines and spaces only for seven pitches A, B, C, D, E, F, and G (five of which are a whole step from the following tone), three additional symbols are used. Placed next to a note, they alter its meaning, permitting the notation of the remaining pitches. They are the flat (
), which lowers the pitch of a note by a semitone; the sharp (), which raises it by a semitone; and the natural (), which cancels a previous flat or sharp. If certain flats or sharps appear regularly throughout a piece, their signs are placed next to the clef, in a key signature.

The durations of notes are indicated by their specific shapes; the durations of silences are set forth by signs called rests. The terminology of notes and rests indicates their durational relationships: whole, half, quarter, eighth, sixteenth, thirty-second, sixty-fourth, each being double or half the value of its neighbor in the series. Meter, the grouping of musical beats into basic recurrent units, is also indicated. A time signature, which shows how the beats are to be grouped, is placed on the initial staff next to the key signature; and vertical lines (bar lines) mark off the metrical units, or measures. The time signature also indicates a system of stresses: The first beat of a metrical grouping is usually the strongest. Additional symbols indicate other aspects of the music.


                III            HISTORY  

Today's system developed over many centuries. The note shapes are derived from neumes, handwritten signs that were placed over the words of medieval chant. At first neumes gave only a vague indication of melodic directions and patterns. Gradually the shapes became more precise and, about AD1000, staff lines were added: first one, then two, then four and five. By about 1200, the notation was reasonably exact as to pitch, but quite vague regarding duration.

About that time the earliest durational notation appeared. Called modal notation, it specified a constantly repeated rhythmic mode, or pattern. About 1250 four durational note and rest shapes were established, as well as a set of rules for determining whether a given note should subdivide into two or three shorter notes. Additional symbols for smaller durations were soon added. Although this system measured duration, somewhat variably, it did not include metrical stress. Time signatures that regulated duration first appeared in 14th-century France. Each signature represented three levels of subdivision. Eventually one level was discarded. Most modern time signatures represent a basic unit plus one level of subdivision. With the introduction in the mid-15th century of white note heads (that is, unfilled outlines) in addition to the solid-color note heads already in use, the system was very close to modern notation.

During the 17th and 18th centuries the final changes to modern key and metrical time signatures occurred. By the mid-18th century, subsidiary instructions as to tempo, articulation, performing techniques, and expressiveness were commonly added. The use of such symbols greatly accelerated in the 19th century.

In the mid-20th century, critics pointed out that contemporary music was not well served by a system that was based on the seven unevenly spaced pitches of medieval music. The same criticism applied to rhythm subdivisions that were mostly duple and that treated tempo, dynamics, and articulation only vaguely.


                IV            OTHER NOTATIONAL SYSTEMS  

Alphabetical notations were used in ancient Greece and elsewhere. Jazz charts may indicate only the harmonic structure, leaving all the rest to the performer. In addition to their western uses, neumes have also been employed in China, Japan, and the Near East as well as for Tibetan chant.

Tablatures are compact notations that use signs, numbers, or letters, usually to notate fingerings rather than pitches. Modern popular guitar tablature is a small grid in which vertical lines represent the strings and horizontal lines represent the frets; black dots indicate where to put the fingers.

Writers discussing music sometimes use the following system to specify pitches: CC-BB = third C through third B below middle C; C-B = second C through second B below middle C (that is, C = C below the bass staff); c-b = C through B below middle C; c1-b1 = middle C through the B above it; c2-b2 = C above middle C through the B above that; c3-b3 = second C above middle C through the B above that (that is, c3 = C above the treble staff).

In the 20th century, composers of "indeterminate" compositions leave many elements deliberately vague and to chance; this is also true of their unconventional notation.


Musical Rhythm, all aspects of music concerned with its motion through time and, thus, with its time structure. In addition to this overall meaning, the term rhythm is occasionally used to refer to specific time events, such as the patterns of lengths in a certain group of notes.


                II             PULSE AND METER  

Like the rhythms in nature, such as the motion of the planets, the succession of seasons, and the beating of the heart, musical rhythm usually is organized in regularly recurring patterns. Such patterns regulate the motion of the music and aid the human ear in grasping its structure. The most basic rhythmic unit is the beat or pulse—a recurring time pattern that resembles the ticking of a clock. In most popular and dance music, the pulse is explicitly stated, often by drumbeats or by a regular accompaniment pattern. In more complex music, the beat is often only implicit—a kind of common denominator for the actual lengths of the notes, which may be longer or shorter than the pulse itself. (When the listener taps a foot to such music, however, the pulse again becomes explicit.) For the pulse to be heard as a common denominator, the lengths of the individual notes must be its exact multiples or subdivisions (such as two short notes, each half as long as the pulse, or a note twice the length of the pulse). The tempo of the music determines the speed of the beat. In a fast tempo, the beat has a relatively short time value; in a slow tempo, the value of the beat is longer.

Just as the beats regulate the durations of such short musical events as a note or a pair of notes, the beats themselves are regulated by larger recurring units called measures. Measures are formed by stressing the first in a series of two or more beats, so that the beats group themselves into a pattern, for example; ONE two, ONE two, or ONE two three, ONE two three. (The first beat is called the downbeat of the measure; the last beat is called the upbeat.) The term meter can refer, first, to this general process of regular accentuation, and second, to the particular metrical grouping used in a given piece. In musical notation, meter is indicated by the time signature. In the time signature , for example, the lower number, 4, indicates that the basic pulse is written as a quarter-note; the upper number, 2, indicates that each measure has two quarter notes. Similarly, in  meter (or  time) each measure has six eighth-notes. In meters such as , which are considered more complex and are known as compound meters, each measure has, in addition to the principal accent on the first beat, one or more subsidiary accents. Thus a  measure has a primary accent on the first beat and a secondary accent on the fourth beat: ONE two three, Four five six.

Metrically organized music is highly structured and tends to be regular. Once the meter is established, however, it need not be rigidly adhered to at all times; the listener's mind will retain the pattern even if the music temporarily contradicts it. Thus, a normally weak beat can be stressed, producing a syncopation (an accent that works against the prevailing meter). Conversely, a strong beat may occasionally be suppressed completely. Indeed, in complex metrical music a degree of tension always exists between, on the one hand, the meter as an abstract system of regulation and, on the other hand, the rhythmic flow of the actual note lengths—a flow that at times supports the meter and at times does not. Furthermore, the pulse need not necessarily be maintained with absolute rigidity; it may be played rubato, that is, with variations so slight that they do not destroy the basic value.


                III            LARGER TIME UNITS  

Just as beats are grouped into measures, measures are themselves grouped into larger units. Such groupings produce the more extended segments of time that determine the form of the music. A motive (the shortest melodic idea that forms a relatively complete musical unit) may consist of more than one measure. One or more motives may be repeated and varied to form a phrase (a yet larger unit with a still more definite sense of ending, corresponding roughly to a sentence in language). Phrases are combined to produce sections, and sections are combined to produce entire compositions. Musical form is shaped by the relationships among these various time units and also by the relationship of these units to the whole; form in music is thus basically rhythmic in nature.

                IV            WESTERN USE OF RHYTHM  

From the middle Ages to the present, Western music has consisted primarily of multipart music, in which two or more melodies are performed simultaneously, or else a melody is combined with accompaniment. This means that more than one note sounds at once. Moreover, the relationship of the simultaneous notes must conform to the requirements of Western music's highly developed system of harmony. These facts made necessary the development of a system of rhythm that could precisely regulate the various parts, allowing them to move independently, yet in strictly controlled coordination. The previously described metrical system, with its common underlying time-length framework, provided an ideal means for such coordination. Western music also required a notational system in which large numbers of mutually related time values could be indicated exactly; this is called Musical Notation. The Western system of rhythm has thus been to some extent a matter of rational control and measurement. It has also made possible the creation of extended multipart compositions of great technical and dramatic complexity.


                V             20TH-CENTURY TRENDS  

In the 20th century various composers tried to break away from what they considered the overly regular quality of metered music. One way was to alter the lengths of measures, creating a kind of variable meter. Thus, a series of four measures might have time signatures of , , , and . The only common denominator is the eighth-note of the pulse itself, which is added to produce a series of irregular larger groupings: 3 + 4 + 2 + 5. Another technique is polymeter, the simultaneous use of different meters in different parts. A more extreme approach, found in some music after about 1950, avoids meter entirely. Performers are allowed to fit a certain number of notes within a given time span (such as 10 seconds) at will, without following rules for exact coordination or measurement of the durations.


                VI            NON-WESTERN SYSTEMS  

In a sense, recent Western music seems to be coming closer to non-Western music, much of which is to some degree nonmetric, and in which improvisation is often important. Some musical cultures limit music to a single line of melody, with a small number of note lengths (in some cases, only two, one twice as long as the other). The note lengths, however, can be combined in various ways to create flexible, irregular larger patterns that are somewhat reminiscent of those found in Gregorian chant in early Western music.

In India and Japan, in different ways, rhythm is highly systematized yet still preserves a degree of flexibility that transcends that of most Western music. In Indian music, for example, the durations are organized within a recurring time cycle known as a tala. Although tala has something in common with the Western measure, its patterns are usually considerably longer. Moreover, its subdivisions consist of units of unequal length that combine to form a freely flowing musical continuum within the tala.

Other cultures have developed highly complex multipart music. African music, for instance, is largely improvised, the various parts being held together by a constant basic unit beaten out on a drum or by handclaps. The other parts are structured with great freedom relative to this unit, producing their own metrical patterns that only occasionally coincide with one another and with the basic pulse. Although this system makes it impossible to produce the elaborate harmonic effects characteristic of metrical multipart music, it results in a rhythmic structure that is considerably more complex and varied.


                                                                Western Music


Western music is from Europe and other areas of the world settled by Europeans. Western music is one of several separate, highly developed musical cultures, each of which has its own specific theoretical base that encompasses, among other things, its own system of tunings and scales.

                 Although an isolated cuneiform example of Hurrian (Hittite) music of the 2nd millennium BC has been tentatively deciphered, the earliest European music known is that of the ancient Greeks and Romans, dating from about 500 BC to AD300. Fewer than a dozen examples of Greek music survive, written in an alphabetical notation that cannot be deciphered with certainty. Greek and Roman theories of the nature and function of music, however, are discussed at length in the writings of such philosophers as Aristotle, Boethius, Plato, and Pythagoras. These writers believed that music originated with the god Apollo, the mythological musician Orpheus, and other divinities, and that music reflected in microcosm the laws of harmony that rule the universe. They believed, furthermore, that music influences human thoughts and actions. Greek music was primarily monophonic (limited to one melody at a time sung or played without harmony). Occasionally, however, one or more musicians in an ensemble might play a variant of the melody while other musicians were playing its original version. This produced a somewhat more complex musical texture called heterophony.

The rhythm of Greek music was closely associated with language. In a song, the music duplicated the rhythms of the text. In an instrumental piece it followed the rhythmic patterns of the various poetic feet. The internal structure of Greek music was based on a system of modes that combined a scale with special melodic contours and rhythmic patterns. A similar organization exists today in Arab music and Indian music. Because each Greek mode incorporated rhythmic and melodic characteristics, listeners could distinguish between them. Greek philosophers wrote that each mode possessed an emotional quality and that listeners would experience this quality on hearing a composition in that mode. Today, without further knowledge of the music itself, no one can say whether this idea was true in human experience or was only a theory.

The most common Greek instruments were the kithara, a form of lyre associated with Apollo, and the aulos, an oboelike instrument associated with the god Dionysus. The kithara was said to have had a calming or uplifting effect on listeners, and the aulos was said to have communicated excitement. These instruments were used in religious ceremonies as well as in the theater, where they accompanied the performance of Greek dramas. Instrumental playing reached its apex around 300BC, when many musicians participated in contests.

The Romans seem to have carried on the Greek musical traditions and to have contributed little of their own. They did develop some brass instruments, however, which they used in battle and in military processions. They also invented the hydraulis, an organ with a hydraulic air-pressure stabilizer.


                III            EARLY MEDIEVAL PERIOD  

In the Middle Ages most professional musicians were employed by the Christian church. Because the church was opposed to the paganism associated with ancient Greece and Rome, it did not encourage performances of Greek and Roman music. Consequently, this music died out.

Little is known of the unaccompanied chant that was used in services of the early Christian church. Christian chant appears, however, to have been drawn from the ritual music of the Jewish synagogue and from secular tunes of the time. The chant melodies that developed in Rome were inventoried and assigned specific places in church ceremonies during the period from the 5th to the 7th century.


A famous and well known chant is the Gregorian Chant, It was originally known as the Roman chant until Pope Gregory I, (known as “The Great”) who may have composed some of the melodies and who actively encouraged an orderly, ritualized use of music by the church.  Because Gregory and later popes preferred Gregorian chant to the varieties that had developed elsewhere in Europe, Gregorian chant eventually superseded most of the others. Gregorian and other chant styles are preserved in many manuscripts. The musical signs used in these manuscripts, called neumes, are the earliest roots of modern musical notation.

By as early as the 9th century, many musicians began to feel the need for a more elaborate music than unaccompanied melody. They began to add an extra voice part to be sung simultaneously with sections of the chant. The musical style that resulted is called organum. In early organum the added voice part simply paralleled the chant melody but was sung a fourth or fifth above it. Later the extra part became an independent countermelody. Organum was important in the history of music, because it was the first step toward the development of the musical texture known as polyphony (multipart music), the extensive use of which is the most distinctive feature of Western music.

Around the end of the 12th century, organum was being written in three and four voice parts, forming long works that could fill the vast spaces of Gothic cathedrals with large quantities of sound. The principal centers in the development of organum were in France, at the Abbey of Saint Martial in Limoges and at the Cathedral of Notre Dame in Paris. An English version of organum, called gymel, had also developed by this period.

In order for musicians to be able to read and perform several different voice parts simultaneously, a precise system of musical notation had to be developed. The notation of pitch had been solved by the use of a musical staff of four, five, or more lines, with each line or space representing a specific pitch, as in present-day notation. The perfection of this system is attributed to the 11th-century Italian Benedictine monk Guido d'Arezzo. Time values proved to be more difficult to notate. The solution that evolved in the 11th and 12th centuries was based on a group of short rhythmic patterns called rhythmic modes. The same pattern, or mode, was repeated over and over until the composer indicated by a sign in the notation that another rhythmic mode was to supersede it. In music using this "modal notation," a variety of rhythmic movement was achieved by employing different modes simultaneously in different voice parts and by changing modes during the course of a composition. By the late 13th century modal notation had been abandoned, and the beginnings of the modern system of long and short note values had come into use.

Organum was a sophisticated musical development that was encouraged and appreciated primarily by the educated clerics in the Christian church. A secular musical tradition, simpler in makeup, existed outside the church. This was the monophonic music of itinerant musicians, the jongleurs and their successors, the troubadours and trouvères of France and the minnesingers of Germany.

Both sacred and secular music used a wide variety of instruments, including such string devices as the lyre and psaltery and the medieval fiddle, or viele. Keyboard instruments included the organ. Percussion instruments included small drums and small bells.


                IV            LATE MEDIEVAL MUSIC  

A major stylistic change occurred in music during the early 14th century. The new style was called ars nova (Latin, "new art") by one of its leading composers, the French prelate Philippe de Vitry. The resulting music was more complex than any previously written, reflecting a new spirit in Europe that emphasized human resourcefulness and ingenuity. De Vitry also invented a system that included time signatures. This allowed musicians of the 14th century to achieve a new rhythmic freedom in their compositions.

The new complexities took several forms. Expanding on the principle of short rhythmic modes, composers of ars nova used rhythmic patterns of a dozen or more notes, which they repeated over and over in one or more voice parts of a composition. The new principle is called isorhythm (Greek iso,"same"). Composers used an isorhythmically organized voice part as the foundation for large works and wove other melodies over it to produce intricate polyphonic designs. The foundation voice was usually taken over from a portion of Gregorian chant. This borrowed melody was known as the cantus firmus (Latin, "fixed melody"). The musical genre in which composers used the isorhythmic principle to the greatest extent was the motet. Some motets, in addition to complexities of structure, contained several texts sung simultaneously.

A second complexity of ars nova concerned the overall structure of music written for the mass. Before 1300, polyphonic settings had sometimes been written for separate sections of the mass. In the 14th century, for the first time, all five sections that make up the Ordinary of the mass were treated as an integrated whole. The first person to do this was the French cleric, poet, and composer Guillaume de Machaut. His example, however, was not followed until the next century.

A distinctive feature of the ars nova was the increased attention given to secular music. For the first time the major composers of the period wrote secular as well as sacred music. The unharmonized melodies that had been sung in the 13th century by the troubadours and trouvères were expanded by 14th-century composers into two- and three-voice pieces called chansons (French, "songs"). The patterns of line repetition in the texts for these chansons determined the overall form of the music. The most commonly used schemes in France were the rondeau, the virelai, and the ballade. In Italy the madrigal, the caccia, and the ballata were the preferred types. The foremost Italian composer of the period was Francesco Landini.


                V             THE RENAISSANCE  

Reacting against the complexities of the ars nova, most early 15th-century composers preferred a simpler style of music with smoothly flowing melodies, smoother-sounding harmonies, and less emphasis on counterpoint. The first major impetus toward a simpler style came from the English composer John Dunstable. The graceful aspects of his style were soon adopted by composers on the continent of Europe, especially those employed by the dukes of Bourgogne in northeastern France. These Bourguignon composers were noted for their chansons, in which one voice part acted as a principal melody and one or two other parts served as an accompaniment. The Bourguignons also developed the practice, begun by Machaut, of composing unified settings of the Ordinary of the mass. As a result of their activities, the mass became a monumental genre comparable in scope to the symphonies of the 19th century. Masses that used a cantus firmus were often based on chansons or other secular melodies rather than on Gregorian chant. This fact reflected the increasing influence of secular interests during the Renaissance.

In writing contrapuntal music, Renaissance composers relied heavily on imitation, the successive, closely spaced restatement in one or more voice parts of the same melodic idea. The technique of imitation had been in use since the late 14th century, but during the Renaissance it became a principal structural element in music. If one voice part imitated another consistently for a relatively long span of time, the two voices formed a canon. Pairs of voices in Renaissance music sometimes moved in canon throughout an entire piece or section while shorter imitations were occurring among the other voice parts.

The most versatile early Renaissance composer was Guillaume Dufay. He wrote motets that approached the complexity of the style of ars nova as well as chansons in the newer, lighter manner. The outstanding composer of chansons was Gilles Binchois.

The influence of Bourguignon composers declined by the mid-15th century. From about 1450 until about 1550 most of the important musical posts in Europe were held by composers born in present-day Holland, Belgium, and the adjoining French territories. These composers are often called Netherlanders after the name of their native region.

In general, the Netherlanders preferred a homogeneous sound, for example, that made by an unaccompanied chorus. The predominant texture of their music was contrapuntal, with all voice parts equal in importance. These musical features contrasted with the typical Bourguignon sound, in which each voice part had its own color (for instance, a solo voice accompanied by two different solo instruments), and in which one voice dominated the others.

The Netherlanders continued the Bourguignon tradition of composing chansons, motets, and masses. Although many excellent masses were composed in the late 15th and 16th centuries, the mass was not as exciting a challenge then as it had been to the Bourguignons. The basic techniques for unifying an entire mass had become the common property of all composers, and mass texts, which always remain the same, suggested fewer new kinds of musical setting. Largely for these reasons, the motet became the vehicle for experimentation. The texts, drawn from all parts of the Bible as well as from other sources, evoked many illustrative musical ideas from composers. Chansons of the 16th century moved away from the simple charm of the Bourguignon love songs. They tended either to be elaborately contrapuntal or else filled with witty musical allusions to birdcalls, the cries of street vendors, and so forth. The chansons of the Parisian composers Claudin de Sermisy and Clément Janequin exemplify the latter style.

The leading Netherlanders were Johannes Ockeghem, Jakob Obrecht, Josquin Desprez, and Orlando di Lasso. Among the most prominent Italian musicians of the late Renaissance was Giovanni da Palestrina. His music typifies the even flow of choral polyphony that was the chief ideal of the Renaissance musical style. Other noted musicians of the time included the English organist and composer William Byrd and the Spanish composer Tomás Luis de Victoria. Important to the growth of music was the development of techniques for printing musical compositions. First devised about 1500 by the Venetian printer Ottaviano dei Petrucci, such techniques were soon in use in Antwerp, Nürnberg, Paris, and Rome.


                VI            THE BAROQUE ERA  

In the late 16th century, when Renaissance polyphony was prevalent, new developments in Italy were beginning to change the sound and structure of music.  Many Italian musicians disliked the polyphonic style of the Netherlanders. Wishing to emulate their image of classical Greek music, they favored less intricate compositions marked by frequent emotional contrasts, a readily understandable text, and an interplay of various voices and instruments. Such elements became especially prominent in opera, a genre first performed in Florence at the end of the 16th century and greatly developed in the 17th century by the Italian composer Claudio Monteverdi.  Other new genres of vocal music included the cantata and the oratorio.

Instrumental music also became increasingly prominent during the 17th century, often in the form of a continuous contrapuntal work with no clear-cut divisions into sections or movements; it bore such names as ricercare, fantasia, and fancy. A second type of composition was made up of contrasting sections, usually in both homophonic and contrapuntal textures; this type was known as the canzona or sonata. Many instrumental pieces were based on an already existing melody or bass line; they included the theme and variations, passacaglia, chaconne, and chorale prelude. Pieces in dance rhythms were often grouped together into suites. Finally, composers developed pieces in improvisatory styles for keyboard instruments; these pieces were called preludes, toccatas, and fantasias.

With the rise of new genres in the 17th century, some of the basic concepts of musical structure were transformed, especially in Italy. Instead of writing pieces in which all voices from soprano to bass participated equally in the musical activity, composers concentrated on the soprano and bass parts and merely filled in the remaining musical space with chords. The exact spacing of the chords was unimportant, and composers often allowed a keyboard player to improvise them. The terms basso continuo, thoroughbass, and figured bass refer to the bass line and the chordal filling, which formed a texture used in all types of music, particularly in solo songs.

Another important 17th-century innovation changed the fluid style of much late Renaissance music into one marked by numerous contrasting elements; it was known variously as concertato, concertate, and concerto, from concertare (Latin, "to struggle side by side"). The contrasts occurred on many musical levels, such as contrasting instruments or contrasting densities of sound, with, for example, a single instrument opposed by a group of instruments; contrasting rates of speed; and contrasting degrees of loudness. These contrasting features were made to compete or alternate with one another in order to produce an aggressive, excited musical style, which was applied to music for all instruments as well as for the voice and was used in all forms and genres.

Outstanding composers of the 17th and early 18th centuries included the following: the Italians Arcangelo Corelli, Alessandro Scarlatti, Domenico Scarlatti, and Antonio Vivaldi; the Germans Dietrich Buxtehude and Heinrich Schütz; the Englishman Henry Purcell; the Italian-Frenchman Jean Baptiste Lully; and the Frenchman Jean Philippe Rameau.

Toward the end of the 17th century, the system of harmonic relationships called tonality began to dominate music. This development gave music an undercurrent of long-range relationships that helped to smooth out some of the abruptness of contrasts in the earlier baroque style. By the early 18th century composers had gained a firm control over the complex forces of tonality. By this time, too, they had largely abandoned the idea of frequent shifts in mood and had begun to favor a more moderate and unified approach. Often an entire piece or movement was an elaboration of one emotional quality, called an affect. The control over tonality and the emphasis on single moods were largely responsible for the feeling of security and inevitability in the music of this time, including the music of the two greatest late baroque German composers, Johann Sebastian Bach and George Frideric Handel.



Beginning around 1720 new developments once again began to undermine the prevailing musical style. Younger musicians found baroque counterpoint too rigid and intellectual; they preferred a more spontaneous musical expression. In addition, the late baroque ideal of establishing a single emotional quality and maintaining it throughout a composition seemed constricting to these younger composers.

The reaction against baroque style took different forms in France, Germany, and Italy. In France the new current, often called rococo or style galant (French, "courtly style"), was represented by the French composer François Couperin. This style emphasized homophonic texture, that is, melody with chordal accompaniment. The melody was ornamented with embellishments such as short trills. Instead of an uninterrupted stream of music, as in a baroque fugue, French composers wrote pieces consisting of combinations of separate phrases, as in music for dance. The typical composition was short and programmatic, that is, it portrayed nonmusical images such as birds or windmills. The harpsichord was the most popular instrument, and many suites were written for it.

In northern Germany the preclassical style was called empfindsamer Stil (German, "sensitive style"). It encompassed a wider range of contrasting emotions than the style galant, which tended to be merely elegant or pleasant. German composers usually wrote longer compositions than the French and used a variety of purely musical techniques to unify their pieces. They did not rely on nonmusical images, as did the French. The Germans thus played a significant role in the development of abstract forms, such as sonata form, and in the development of large instrumental genres, such as concerto, sonata, and symphony.

In Italy the preclassical style did not have a special name, perhaps because it did not break sharply with music of the immediate past. Italian composers, however, contributed a great deal to the development of new genres, especially to the symphony. The Italian opera overture, often called a sinfonia, usually had no musical or dramatic connection with the opera it introduced. Italian musicians sometimes played opera overtures in concerts, and composers eventually began to write independent instrumental pieces following the format of the overture. This format consisted of three movements, the first and last in fast tempos, and the middle one in a slow tempo. Within each movement the progression of musical ideas usually followed a pattern that eventually evolved into sonata form.

Once Italian composers had established the idea of writing an independent instrumental sinfonia, the Germans took over the idea and applied much intellectual ingenuity to it. The principal German centers of activity were at Berlin, Mannheim, and Vienna. Largely as a result of German activities, differentiated musical forms, genres, and media arose. A distinction was made between the medium of chamber music, in which one instrument plays each part, and the medium of symphonic music, in which several instruments play each part. Within the category of chamber music, composers began to distinguish among several media, such as the string quartet, the string trio, and the keyboard sonata with violin obbligato. For the orchestral medium, composers wrote not only symphonies but also concertos for solo instrument and orchestra.

The symphony, sonata, concerto, and string quartet all followed similar formal outlines. They were in three or four movements, one or more of which was in sonata form. Made possible by the sophisticated use of tonality that had developed by the end of the baroque era, sonata form arose in the mid-18th century and exploited the complex web of harmonic relationships among separate tones and chords within a key, and among different keys. Sonata form was based on a movement away from and back to a principal key. To this was added the statement of opposing themes at the outset of a movement and the elaboration or separate development of one or all later on.

The climax of 18th-century musical development came at the end of the century in the music of a group of composers known as the Viennese classical school. The most important of these composers were Joseph Haydn, Wolfgang Amadeus Mozart, and Ludwig van Beethoven.

Opera in the 18th century also underwent many changes. In Italy, where it was born, opera had lost much of its original character as a drama with music. Instead it had become a series of arias designed to display the talents of singers. Several European composers reintroduced instrumental interludes and accompaniments as an important element. They made greater use of choral singing and introduced greater variety into the forms and styles of the arias. They also tried to combine groups of recitatives, arias, duets, choruses, and instrumental sections into unified scenes. The most important reformer was the Bavarian-born Christoph Willibald Gluck, whose most influential operas were written in Vienna and Paris from 1764 to 1779. Opera in the classical period climaxed in the stage works of Mozart, in which every aspect of the vocal and instrumental lines contribute to the plot development and characterization.


                VIII         THE ROMANTIC ERA  

At the beginning of the 19th century, the Viennese classical style as exemplified in Haydn, Mozart, and Beethoven prevailed throughout Europe. This style provided so satisfactory a means for achieving the musical goals of the time that almost every composer wrote in some variation of it. The style tended to become a mere formula in the hands of less skilled composers. Partly for this reason, experimenting musicians between 1810 and 1820 gradually began to reach out in new directions.

The more adventurous musicians no longer felt that it was essential to coordinate all elements in their music so as to maintain clear formal outlines. They began to value other musical goals more than the goal of formal clarity. Instead of moderation, they began to value such qualities as impulsiveness and novelty. They might, for instance, write an unusual progression of chords even though the progression did not contribute to the overall harmonic direction of a composition. Similarly, if the sound of a particular instrument seemed especially attractive during the course of a symphony, they might write a long solo passage for this instrument, even though the solo distended the shape of the symphony. In this and other ways 19th-century composers began to exhibit a romantic, as opposed to a classical, view of their art. The aesthetic goals of romanticism were especially valued in Germany and central Europe. The instrumental works of Franz Schubert, an Austrian, and the piano music and operas of Carl Maria von Weber, a German, were an early manifestation of this development in music.

The romantic composers were often inspired by literary, pictorial, and other nonmusical sources. Consequently, program music, or music that follows a nonmusical plan, was widely cultivated, leading to the development of the symphonic poem. The French composer Hector Berlioz and the Hungarian composer Franz Liszt became especially prominent in this genre.  Poetry of the 18th and 19th centuries formed the basis of art songs in which the composer portrayed with music the imagery and moods of the texts.  The German art song is known by its German name, lied. Many hundreds of lieder were composed in the 19th century, the most successful being written by Schubert, Robert Schumann, Johannes Brahms, Hugo Wolf, and, late in the century, Richard Strauss.

The ideal 19th-century genre was opera. Here, all the arts were joined together to produce grand spectacles, highly charged emotional situations, and opportunities for spectacular singing. In France, Gasparo Spontini and Giacomo Meyerbeer established the style called grand opera. Another Frenchman, Jacques Offenbach, developed a comic-opera style called opéra bouffe. Other important French opera composers were Charles Gounod and Georges Bizet. In Italy, Gioacchino Rossini, Gaetano Donizetti, and Vincenzo Bellini continued the 18th-century Italian tradition of bel canto (Italian, "beautiful singing"). In Italy during the second half of the century, Giuseppe Verdi tempered the emphasis on bel canto by stressing the dramatic values inherent in human relationships. Sentimental love and violent emotions were stressed by Giacomo Puccini. In Germany, Richard Wagner created an opera style called music drama, in which all aspects of a work contributed to the central dramatic or philosophical purpose. Unlike Verdi, who stressed human values, Wagner was usually more concerned with legend, mythology, and such concepts as redemption. Wagner developed the use of short fragments of melody and harmony, called leitmotifs (German, "leading motives"), to represent people, objects, concepts, and so on. These fragments were repeated in the vocal or orchestral parts whenever the thing they represented recurred in the actions or thoughts of the characters.

During the 19th century a tradition of abstract, or nonrepresentational, music was maintained in symphonies and chamber music. Schubert, Schumann, Brahms, the German composer Felix Mendelssohn, and the Austrian composer Anton Bruckner were especially important in this regard. The Russian composer Peter Ilich Tchaikovsky wrote symphonic and chamber works as well as operas and program music. Works without programs but with freely devised forms were written for the piano by the Polish composer Frédéric Chopin.

In all musical genres, a high value was placed on uniqueness of expression. This gave rise not only to widely differing personal styles of composition but to personality cults of virtuoso performers and conductors. Two of the best known were Liszt and the Italian violinist Nicolò Paganini. The Austrian conductor and composer Gustav Mahler wrote symphonies that incorporated references to his personal life.

By the end of the century the romantic style had modified the language of music in several ways. The taste for unusual chord progressions had brought about a disintegration of tonality. Composers, especially Wagner, made increasing use of chromaticism, a harmonic style with a high proportion of tones outside the prevailing key. Folk music idioms became widespread, particularly on the part of composers from Russia, Czechoslovakia, Norway, and Spain. Among these composers were the Russians Mikhail Glinka, Modest Mussorgsky, and Nikolay Rimsky-Korsakov; the Czechs Antonin Dvoøák and Bedøich Smetana; and Edvard Grieg, a Norwegian. Later composers who made use of folk elements included Louis Moreau Gottschalk, an American; Carl Nielsen, a Dane; Jean Sibelius, a Finn; and Manuel de Falla, a Spaniard.

These folk idioms, along with others discovered at the beginning of the 20th century, reintroduced into art music many older concepts of harmony and rhythm. The same effect resulted from systematic researches into the history of music, which were begun in the 19th century. With the disintegration of tonality, cohesion in a piece of music was less and less dependent on harmonic movement and more and more dependent on the ebb and flow of intensities and densities of sound. The use of sound as a structural element in music was one characteristic of the late romantic French style called impressionism, which was developed by Claude Debussy and Maurice Ravel. Other French composers worked in a more satirical style; these included Francis Poulenc and Erik Satie.


                IX            THE 20TH CENTURY  

The high value placed on individuality and personal expression in the romantic era has grown even more pronounced in the 20th century. This is partly the result of several features of 20th-century life. In this era more people from more social and geographic backgrounds than ever before have been able to study music and develop their aptitude for composition. An enormous range of tastes and skills has thus become a feature of modern composition. Radios and recordings bring music from once-remote countries in South America and the Far East to the attention of musicians in all parts of the world. The speed of modern communications makes it possible for listeners to evaluate innovations more quickly than ever before. The result of these features is that originality is more highly valued than in any previous era, and that diversity and rapid change have become the most prominent general features of 20th-century music.

Several styles that have played a significant role during the century have names that refer to their harmonic characteristics. Chromaticism has continued to be a prominent feature of harmony in the 20th century. In the first decade of the century, largely as a result of extreme chromaticism, atonality, or the complete absence of tonality, occurred in the music of a few composers. The most notable atonal composer of that time was Arnold Schoenberg, an Austrian.

In the early 1920s Schoenberg devised the twelve-tone method of writing atonal music. In this method, the 12 tones into which the octave is divided are placed in a row following any order of the composer's choosing. The composer then adheres to this succession, or a variation of it. Several successive tones may be combined into chords to avoid merely repeating the entire row as a melodic line. Schoenberg developed the twelve-tone method partly to prevent himself from unconsciously slipping back into tonal patterns of thought and partly to enable himself to organize large spans of atonal music in a coherent manner. At first, Schoenberg's pupils, such as the Austrian composers Alban Berg and Anton von Webern, were the only ones who adopted his technique. Within 30 to 40 years of its appearance, however, most major composers of the 20th century had used the method.

The other harmonic styles in 20th-century music include polytonality, or the simultaneous use of more than one tonality, and modality, or the use of modes and scales from the Renaissance and earlier. The Hungarian composer Béla Bartók based much of his harmonic style on the modes of old Hungarian folk music.

Microtonal music, another 20th-century innovation, is also based on a harmonic concept. In microtonal music, however, the octave has been divided into more than the usual 12 tones, which means that some of the tones, the so-called microtones, sound slightly sharp or flat when compared with the tones of a normal Western scale.

Neoclassicism, which developed in the 1920s, is a comprehensive style involving more than harmonic features. It marked a return to the classic concept that all elements in a composition should contribute to the clarity of the overall structure of form. Neoclassicism included the use of a modified sense of tonality, usually enlivened with a large amount of chromaticism, and the use of formal schemes from the baroque and classical eras. The most prominent representatives of neoclassicism were Igor Stravinsky and the German-born Paul Hindemith. Others included the Russian Sergey Prokofiev and Dmitry Shostakovich. Many American composers have embraced the principles of neoclassicism, largely as a result of their years of study in Paris with the French composer-teacher Nadia Boulanger. These Americans included Elliott Carter, Aaron Copland, Walter Piston, and Virgil Thomson.

Beginning in 1948, the French engineer and composer Pierre Schaeffer and a few other composers in Paris began to record sounds such as street noises and to combine them in various ways. They called the result musique concrète (French, "concrete music") because their music consisted of sounds from everyday life rather than abstract and artificial sounds as produced by musical instruments. Musique concrète marked the beginning of electronic music, in which electronic equipment, including computers, is used to generate sounds, modify them, and combine them with each other. By the late 1960s many hundreds of studios in all parts of the world had been equipped with electronic equipment for composers to use.

Two other innovations in 20th-century music are serialism and indeterminacy, or chance. Serialism is based on the principle of the twelve-tone method. An order of succession is established for rhythmic values for levels of loudness, for example, as well as for pitches. All of these so-called rows are then repeated during the course of the work. The technique is sometimes called total serialism to distinguish it from the limited serialism involved in the twelve-tone method. The serial composers have included Olivier Messiaen and his pupil Pierre Boulez, both French; Karlheinz Stockhausen, a German; Ernst Krenek, an Austrian; and Milton Babbitt, an American.

Music involving indeterminacy leaves some aspect of the music to chance. The role of chance may take many different forms. For instance, during the process of composition the composer might base some choices of sounds on the outcome of a game of dice or cards; or the composer might write several pages of music and let the performer choose which pages to play and the order in which to play them. Or, instead of using traditional musical notation, the composer might prepare a design of lines and shapes and ask the performer to devise some combination of sounds that will be equivalent to the design. The composers who use indeterminate procedures have included the Americans, John Cage and Earle Brown. Other composers such as the Argentine Alberto Ginastera and the Greek Yannis Xenakis have written music with certain indeterminate elements. Most composers in the late 20th century freely draw on serial, electronic, indeterminate, and other techniques.

Opera has suffered in the 20th century from rising labor costs and declining subsidies, which were generously provided in previous centuries from royal and state treasuries. The genre nevertheless remains so attractive that only a handful of important 20th-century composers have not written at least one opera. Those 20th-century composers whose operas have proven most popular include the German composers Richard Strauss and Hans Werner Henze and the British composer Benjamin Britten. Music for the dance, previously neglected by most major composers except Tchaikovsky, began to receive the attention of most 20th-century composers, notably Prokofiev, Ravel, and Stravinsky.

Although music in the 20th century seems to encompass a bewildering variety of procedures and approaches, one feature has emerged since 1950 as common to most progressive works. This is the emphasis on sounds, their qualities, textures, densities, and durations. For the first time in the history of Western music, this element has begun to take precedence over all others, including melody, which may not be present at all, and harmony, which may be treated merely as one component in a series of sound complexes.