20th-century music
During the 20th century there was a large increase in the variety of music that people had access to. Prior to the invention of mass market gramophone records and radio broadcasting, people mainly listened to music at live Classical music concerts or musical theatre shows, which were too expensive for many lower-income people; on early phonograph players ; or by individuals performing music or singing songs on an amateur basis at home, using sheet music, which required the ability to sing, play, and read music. These were skills that tended to be limited to middle-class and upper-class individuals. With the mass-market availability of gramophone records and radio broadcasts, listeners could purchase recordings of, or listen on radio to recordings or live broadcasts of a huge variety of songs and musical pieces from around the globe. This enabled a much wider range of the population to listen to performances of Classical music symphonies and operas that they would not be able to hear live, either due to not being able to afford live-concert tickets or because such music was not performed in their region.
Sound recording was also a major influence on the development of popular music genres, because it enabled recordings of songs and bands to be inexpensively and widely distributed nationwide or even, for some artists, worldwide. The development of relatively inexpensive reproduction of music via a succession of formats including vinyl records, compact cassettes, compact discs and, by the mid-1990s, digital audio recordings, and the transmission or broadcast of audio recordings of music performances on radio, of video recordings or live performances on television, and by the 1990s, of audio and video recordings via the Internet, using file sharing of digital audio recordings, gave individuals from a wide range of socioeconomic classes access to a diverse selection of high-quality music performances by artists from around the world. The introduction of multitrack recording in 1955 and the use of mixing had a major influence on pop and rock music, because it enabled record producers to mix and overdub many layers of instrument tracks and vocals, creating new sounds that would not be possible in a live performance. The development of sound recording and audio engineering technologies and the ability to edit these recordings gave rise to new subgenres of classical music, including the Musique concrète and acousmatic schools of electronic composition. In the 1970s, African-American hip hop musicians began to use the record turntable as a musical instrument, creating rhythmic and percussive "scratching" effects by manipulating a vinyl record on the turntable.
In Beethoven's and Felix Mendelssohn's time in the 19th century, the orchestra was composed of a fairly standard core of instruments which was very rarely modified. As time progressed, and as the Romantic period saw changes in accepted modification with composers such as Berlioz and Mahler, the 20th century saw that instrumentation could practically be hand-picked by the composer. Saxophones were used in some 20th-century orchestra scores such as Vaughan Williams' Symphonies No.6 and 9 and William Walton's Belshazzar's Feast, and many other works as a member of the orchestral ensemble. Twentieth-century orchestras generally include a string section, woodwinds, brass instruments, percussion, piano, celeste, harp, with other instruments called for occasionally, such as electric guitar and electric bass.
The 20th century saw dramatic innovations in musical forms and styles. Composers and songwriters explored new forms and sounds that challenged the previously accepted rules of music of earlier periods, such as the use of altered chords and extended chords in 1940s-era Bebop jazz. The development of powerful, loud guitar amplifiers and sound reinforcement systems in the 1960s and 1970s permitted bands to hold large concerts where even those with the least expensive tickets could hear the show. Composers and songwriters experimented with new musical styles, such as genre fusions. As well, composers and musicians used new electric, electronic, and digital instruments and musical devices. In the 1980s, some styles of music, such as electronic dance music genres such as house music were created largely with synthesizers and drum machines. Faster modes of transportation such as jet flight allowed musicians and fans to travel more widely to perform or hear shows, which increased the spread of musical styles.
Classical
Modernism
In the early 20th century, many composers, including Rachmaninoff, Richard Strauss, Giacomo Puccini, and Edward Elgar, continued to work in forms and in a musical language that derived from the 19th century. However, modernism in music became increasingly prominent and important; among the most important modernists were Alexander Scriabin, Claude Debussy, and post-Wagnerian composers such as Gustav Mahler and Richard Strauss, who experimented with form, tonality and orchestration. Busoni, Stravinsky, Schoenberg, and Schreker were already recognized before 1914 as modernists, and Ives was retrospectively also included in this category for his challenges to the uses of tonality. Composers such as Ravel, Milhaud, and Gershwin combined classical and jazz idioms.Nationalism
Late-Romantic and modernist nationalism was found also in British, American, and Latin-American music of the early 20th century. Composers such as Ralph Vaughan Williams, Aaron Copland, Alberto Ginastera, Carlos Chávez, Silvestre Revueltas, and Heitor Villa-Lobos used folk themes collected by themselves or others in many of their major compositions.Microtonal music
In the early decades of the 20th century, composers such as Julián Carrillo, Mildred Couper, Alois Hába, Charles Ives, Erwin Schulhoff, Ivan Wyschnegradsky turned their attention to quarter tones, and other finer divisions. In the middle of the century composers such as Harry Partch and Ben Johnston explored just intonation. In the second half of the century, prominent composers employing microtonality included Easley Blackwood, Jr., Wendy Carlos, Adriaan Fokker, Terry Riley, Ezra Sims, Karlheinz Stockhausen, La Monte Young, and Iannis Xenakis.Neoclassicism
A dominant trend in music composed from 1923 to 1950 was neoclassicism, a reaction against the exaggerated gestures and formlessness of late Romanticism which revived the balanced forms and clearly perceptible thematic processes of earlier styles. There were three distinct "schools" of neoclassicism, associated with Igor Stravinsky, Paul Hindemith, and Arnold Schoenberg. Similar sympathies in the second half of the century are generally subsumed under the heading "postmodernism".Experimental music
A compositional tradition arose in the mid-20th century—particularly in North America—called "experimental music". Its most famous and influential exponent was John Cage. According to Cage, "an experimental action is one the outcome of which is not foreseen", and he was specifically interested in completed works that performed an unpredictable action.Some of the composers who influenced John Cage were Erik Satie, Arnold Schoenberg and Henry Dixon Cowell.
Minimalism
Minimalist music, involving a simplification of materials and intensive repetition of motives began in the late 1950s with the composers Terry Riley, Steve Reich, and Philip Glass. Later, minimalism was adapted to a more traditional symphonic setting by composers including Reich, Glass, and John Adams. Minimalism was practiced heavily throughout the latter half of the century and has carried over into the 21st century, as well as composers like Arvo Pärt, Henryk Górecki and John Tavener working in the holy minimalism variant. For more examples see List of 20th-century classical composers.Contemporary classical music
Contemporary classical music can be understood as belonging to the period that started in the mid-1970s to early 1990s, which includes modernist, postmodern, neoromantic, and pluralist music. However, the term may also be employed in a broader sense to refer to all post-1945 musical forms.Many composers working in the early 21st century were prominent figures in the 20th century. Some younger composers such as Oliver Knussen, Wolfgang Rihm, Georg Friedrich Haas, Judith Weir, George Benson, Richard Barrett, Simon Bainbridge, John Luther Adams, Toshio Hosokawa, Bright Sheng, Kaija Saariaho, Tan Dun, Magnus Lindberg, Philippe Manoury, Olga Neuwirth, Rebecca Saunders, David Lang, Hanspeter Kyburz, James MacMillan, Mark-Anthony Turnage, Thomas Adès, Marc-André Dalbavie, Unsuk Chin, Claus-Steffen Mahnkopf, and Michael Daugherty did not rise to prominence until late in the 20th century. For more examples see List of 21st-century classical composers.
Electronic music
For centuries, instrumental music had either been created by singing, or using mechanical music technologies, such as drawing a bow across a string that is strung on a hollow instrument or plucking taut gut or metal strings, constricting vibrating air or hitting something to make rhythmic sounds. In the early twentieth century, electronic devices were invented that were capable of generating sound electronically, without an initial mechanical source of vibration. As early as the 1930s, composers such as Olivier Messiaen incorporated electronic instruments into live performance. While sound recording technology is often associated with the key role it played in enabling the creation and mass marketing of popular music, new electric and electronic sound recording technology was used to produce art music, as well. The musique concrète, developed about 1948 by Pierre Schaeffer and his associates, was an experimental technique using recorded sounds as raw material.In the years following World War II, some composers were quick to adopt developing electronic technology. Electronic music was embraced by composers such as Edgard Varèse, Karlheinz Stockhausen, Milton Babbitt, Pierre Boulez, Bruno Maderna, Henri Pousseur, Karel Goeyvaerts, Ernst Krenek, Luigi Nono, Luciano Berio, Herbert Brün, and Iannis Xenakis. In the 1950s the film industry also began to make extensive use of electronic soundtracks. Major rock groups that were early adopters of synthesizers include The Moody Blues, The Beatles, The Monkees, and The Doors.
Folk music
Folk music, in the original sense of the term as coined in the 18th century by Johann Gottfried Herder, is music produced by communal composition and possessing dignity, though by the late 19th century the concept of ‘folk’ had become a synonym for ‘nation’, usually identified as peasants and rural artisans, as in the Merrie England movement and the Irish and Scottish Gaelic Revivals of the 1880s. Folk music was normally shared and performed by the entire community, and was transmitted by word of mouth.In addition, folk music was also borrowed by composers in other genres. Some of the work of Aaron Copland clearly draws on American folk music.
An important work on registering traditional tunes of the Balkanic region was that of Béla Bartók since it is probably the first composer who was interested in recording audios as well as analysing them from an ethnological point of view.
Bluegrass music
Bluegrass music is a form of American roots music, and a related genre of country music. Influenced by the music of Appalachia, Bluegrass has mixed roots in Irish, Scottish, Welsh, and English traditional music, and was also later influenced by the music of African-Americans through incorporation of jazz elements.Settlers from the United Kingdom and Ireland arrived in Appalachia during the 18th century, and brought with them the musical traditions of their homelands. These traditions consisted primarily of English and Scottish ballads—which were essentially unaccompanied narrative—and dance music, such as Irish reels, which were accompanied by a fiddle. Many older bluegrass songs come directly from the British Isles. Several Appalachian bluegrass ballads, such as "Pretty Saro", "Barbara Allen", "Cuckoo Bird" and "House Carpenter", come from England and preserve the English ballad tradition both melodically and lyrically. Others, such as The Twa Sisters, also come from England; however, the lyrics are about Ireland. Some bluegrass fiddle songs popular in Appalachia, such as "Leather Britches", and "Pretty Polly", have Scottish roots. The dance tune Cumberland Gap may be derived from the tune that accompanies the Scottish ballad Bonnie George Campbell. Other songs have different names in different places; for instance in England there is an old ballad known as "A Brisk Young Sailor Courted Me", but exactly the same song in North American bluegrass is known as "I Wish My Baby Was Born".
In bluegrass, as in some forms of jazz, one or more instruments each takes its turn playing the melody and improvising around it, while the others perform accompaniment; this is especially typified in tunes called breakdowns. This is in contrast to old-time music, in which all instruments play the melody together or one instrument carries the lead throughout while the others provide accompaniment. Breakdowns are often characterized by rapid tempos and unusual instrumental dexterity and sometimes by complex chord changes.
There are three major subgenres of bluegrass and one unofficial subgenre. Traditional bluegrass has musicians playing folk songs, tunes with simple traditional chord progressions, and using only acoustic instruments, with an example being Bill Monroe. Progressive bluegrass groups may use electric instruments and import songs from other genres, particularly rock & roll. Examples include Cadillac Sky and Bearfoot. "Bluegrass gospel" has emerged as a third subgenre, which uses Christian lyrics, soulful three- or four-part harmony singing, and sometimes the playing of instrumentals. A newer development in the bluegrass world is Neo-traditional bluegrass; exemplified by bands such as The Grascals and Mountain Heart, bands from this subgenre typically have more than one lead singer. Bluegrass music has attracted a diverse following worldwide. Bluegrass pioneer Bill Monroe characterized the genre as: "Scottish bagpipes and ole-time fiddlin'. It's Methodist and Holiness and Baptist. It's blues and jazz, and it has a high lonesome sound."
Opera
In the early years of the century, Wagnerian chromatic harmony was extended by opera composers such as Richard Strauss, Claude Debussy, Giacomo Puccini, Ferruccio Busoni, Béla Bartók, Leos Janáček and Hans Pfitzner.Further extension of the chromatic language finally broke with tonality and moved into the style of atonal music in the early operas of Arnold Schoenberg and his student Alban Berg, both of whom adopted twelve-tone technique for their later operas: Schoenberg's Moses und Aron, and Berg's Lulu. Neither of these operas were completed in their composers’ lifetimes, however, so that the first completed opera using the twelve-tone technique was Karl V by Ernst Krenek.
Some of the most important operas of the twenties and thirties were composed by the Russian Dmitri Shostakovich.
At the same time, the neoclassicism that became fashionable in the 1920s is represented by Stravinsky's opera buffa Mavra and his opera-oratorio Oedipus Rex. Later in the century his last opera, The Rake's Progress, also marks the end of the neoclassical phase of his compositions. Other operas of this period by composers identified as neoclassicists include Paul Hindemith's Mathis der Maler, Sergei Prokofiev's Voina y Mir, Bohuslav Martinu's Julietta aneb snár and Francis Poulenc's Les mamelles de Tirésias.
In the sixties, the Bernd Alois Zimmermann opera, Die Soldaten, had a great impact.
One of the most particular operas of the seventies was Le Grand Macabre, by György Ligeti. It deals with the subject of mortality through irony and collage.
The most internationally accepted post–World War II composer of operas was Englishman Benjamin Britten
Popular music
The relationship of classical music and popular music is a controversial question. Richard Middleton writes:Neat divisions between "folk" and "popular", and "popular" and "art", are impossible to find... arbitrary criteria to define the complement of "popular". "Art" music, for example, is generally regarded as by nature complex, difficult, demanding; "popular" music then has to be defined as "simple", "accessible", "facile". But many pieces commonly thought of as "art" have qualities of simplicity; conversely, it is by no means obvious that the Sex Pistols' records were "accessible", Frank Zappa's work "simple", or Billie Holiday's "facile".