Western Music History

I INTRODUCTION Music, Western, the music of Europe and of 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, its preferred timbres (tone colors), its particular approach to musical form, and its characteristic musical textures. As such, Western music stands alongside other major musical systems, notably those of India, Indonesia, Islamic culture, China, and Japan. This article discusses the history of the art music of Western culture. For religious, symbolic, and social aspects of Western music, see Music and see Musical Instruments. For elements of music theory, see Counterpoint; Harmony; Musical Form; Musical Notation; Musical Rhythm. For the music of non-European peoples living in European-settled regions, see African Music; Native Americans: Music and Dance; See also African American Music; American Music; Folk Music; Jazz; Latin American Music; Popular Music. II MUSIC IN ANTIQUITY 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 300 BC, 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. See Greek Music. 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. Roman chant became known as Gregorian chant after Pope Gregory I, 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 at least 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 Burgundy 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 Okeghem, Jacob 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. VII PRECLASSICAL AND CLASSICAL PERIODS 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.