On May 29, 1913, Sergei Diaghilev's Ballets Russes premiered Le Sacre du Printemps at the recently opened Théâtre des Champs-Élysées in Paris — music by Igor Stravinsky, choreography by Vaslav Nijinsky. The opening bassoon solo was met with quiet laughter; within minutes the audience had erupted. Stamping ostinato rhythms in irregular meters, polytonal harmonies grinding against each other, dancers in toe-in primitivist postures depicting a pagan sacrifice — all of it broke from every Romantic-ballet convention the audience expected. Fistfights in the stalls; Nijinsky shouted counts backstage because the dancers could no longer hear the music. The premiere is the most famous opening-night scandal in concert history, and modernist music — the half-century of compositional rupture from roughly 1900 to 1950 — had begun.
Modernism in music was not a single movement but a family of breaks from the Romantic-tonal inheritance. Atonality and the Second Viennese School: Arnold Schoenberg abandoned functional tonality in Pierrot Lunaire (1912) and formalized the twelve-tone technique in 1923 — every pitch class in the chromatic scale appears in an ordered row before any repeats. Alban Berg wrote Wozzeck (1925) in the atonal idiom with retained dramatic intensity; Anton Webern compressed the technique into miniatures of extreme density. After the Rite, Stravinsky moved through Russian-folk sources into neoclassicism (Symphony of Psalms, 1930) and finally adopted twelve-tone serialism in the 1950s. Béla Bartók's folk-modernist synthesis: working with Zoltán Kodály, Bartók collected roughly ten thousand folk songs across Hungary, Romania, Bulgaria, Slovakia, and Turkey, integrating their modal and asymmetric rhythmic vocabulary into highly chromatic art music — Music for Strings, Percussion, and Celesta (1936), the six string quartets, the Concerto for Orchestra (1943). Charles Ives quoted overlapping hymns, marches, and folk tunes in dense polytonal layers. Post-war serialism extended twelve-tone procedures to all musical parameters — Pierre Boulez's Le marteau sans maître (1955) and Karlheinz Stockhausen's Gruppen (1957) applied serial procedures to rhythm, dynamics, and timbre as well as pitch. Indeterminacy was the opposite move: John Cage's Music of Changes (1951) chose pitches by I Ching coin tosses; 4'33" (1952) framed whatever ambient sound the audience heard as the music. Sound mass and sonorism: Krzysztof Penderecki's Threnody for the Victims of Hiroshima (1960) and György Ligeti's Atmosphères (1961) treated tone-colour and texture as primary parameters. Minimalism (1960s+) was the reaction against high serialism: Terry Riley's In C (1964), Steve Reich's phasing in Music for 18 Musicians (1976), Philip Glass's Einstein on the Beach (1976).
Minimalism turned out to be the most commercially and culturally successful of the modernist branches. Philip Glass alone has written over thirty film scores (Koyaanisqatsi, 1982; The Hours, 2002); Reich won the 2009 Pulitzer; Górecki's Third Symphony reached #6 on the UK pop chart in 1992. Modernist sounds shape contemporary film scoring: Kubrick used Ligeti's Atmosphères, Lux Aeterna, and Requiem throughout 2001: A Space Odyssey (1968); Penderecki's Threnody in The Shining (1980). Late-2010s horror-and-sci-fi sound design (Mica Levi on Under the Skin, Jonny Greenwood on There Will Be Blood) draws on modernist sonorism and serial technique. Pop has absorbed modernist techniques selectively — Björk's microtonality, Radiohead's prepared piano on Kid A (2000). The critical question of whether the post-1945 serial consensus was a wrong turn or a necessary phase remains an open argument in musicology.