structural:summarization, quality:correction, quality:corruption
Music

Avant-garde in music can refer to any form of music working within traditional structures while seeking to breach boundaries in some manner. The term is used loosely to describe the work of any musicians who radically depart from tradition altogether. By this definition, some avant-garde composers of the 20th century include Arnold Schoenberg, Richard Strauss (in his earliest work), Charles Ives, Igor Stravinsky, Anton Webern, Edgard Varèse, Alban Berg, George Antheil (in his earliest works only), Henry Cowell (in his earliest works), Harry Partch, John Cage, Iannis Xenakis, Morton Feldman, Karlheinz Stockhausen, Pauline Oliveros, Philip Glass, Meredith Monk, Laurie Anderson, and Diamanda Galás.

There is another definition of "Avant-gardism" that distinguishes it from "modernism": Peter Bürger, for example, says avant-gardism rejects the "institution of art" and challenges social and artistic values, and so necessarily involves political, social, and cultural factors. According to the composer and musicologist Larry Sitsky, modernist composers from the early 20th century who do not qualify as avant-gardists include Arnold Schoenberg, Anton Webern, and Igor Stravinsky; later modernist composers who do not fall into the category of avant-gardists include Elliott Carter, Milton Babbitt, György Ligeti, Witold Lutosławski, and Luciano Berio, since "their modernism was not conceived for the purpose of goading an audience."

The 1960s saw a wave of free and avant-garde music in jazz genre, embodied by artists such as Ornette Coleman, Sun Ra, Albert Ayler, Archie Shepp, John Coltrane and Miles Davis. In the rock music of the 1970s, the "art" descriptor was generally understood to mean "aggressively avant-garde" or "pretentiously progressive". Post-punk artists from the late 1970s rejected traditional rock sensibilities in favor of an avant-garde aesthetic.