Avant-garde jazz (also known as avant-jazz) is a style of music and improvisation that combines avant-gardeart music and composition with jazz. Avant-jazz often sounds very similar to free jazz, but differs in that, despite its distinct departure from traditional harmony, it has a predetermined structure over which improvisation may take place. This structure may be composed note for note in advance, partially or even completely. It originated in the 1950s and developed through the 1960s.
Avant-garde jazz originated in the mid- to late 1950s among a group of improvisors who rejected the conventions of bebop and post bop in an effort to blur the division between the written and the spontaneous. Initially the term was synonymous with free jazz, though it came to be applied to music differing from that style, emphasizing structure and organization by the use of composed melodies, shifting but nevertheless predetermined meters and tonalities, and distinctions between soloists and accompaniment. Musicians identified with this early stage of the style include Cecil Taylor, Lennie Tristano, Jimmy Giuffre, Sun Ra, and Ornette Coleman.
Berendt, Joachim E. (1992). The Jazz Book: From Ragtime to Fusion and Beyond. Revised by Günther Huesmann, translated by H. and B. Bredigkeit with Dan Morgenstern. Brooklyn: Lawrence Hill Books. ISBN 1-55652-098-0