"Alto saxophonist Ornette Coleman's masterpiece, Free Jazz: A Collective Improvisation by the Ornette Coleman Double Quartet, is one of the hinges of jazz evolution. As a musical hinge, Free Jazz, heard from this side of its development, is a bit of an anticlimax compared with the two-label, five album prelude to this point: Something Else!!!! (Contemporary, 1958), Tomorrow is the Question! (Contemporary, 1959), The Shape of Jazz to Come (Atlantic, 1959), Change of the Century (Atlantic, 1959) and This is Our Music (Atlantic, 1959). Had Coleman done nothing else but release these first five recordings, his legacy as one of the pioneers of free jazz would still be assured. But on Free Jazz Coleman took that final step into the chaos of untethered group improvisation and in doing so took the "free" in free jazz as far as it would go. Tenor saxophonist John Coltrane, taking his own route, would do the same five years later with Ascension (Impulse!, 1966)."

- allaboutjazz.com