Posted by Chamber jazz and the Modern Jazz Quartet
Perhaps in reaction to the hot, more strident, more frenetic expressions of the postwar bands, or perhaps as a direct influence of the Thornhill-Evans approach, a cool strain entered the jazz scene in the late 1940s. Generated by Young and furthered by such reed players as Lee Konitz and Gerry Mulligan, cool jazz, along with its structural corollary—contrapuntal, harmonically slimmed-down (often pianoless) chamber jazz—was suddenly in. Understatement and a more relaxed expression replaced extroversion and high-tension virtuosity. Examples abound, beginning with the Miles Davis Nonet (1948–50)—a direct offspring in instrumentation and musical intent of the Thornhill band. In such pieces as “Boplicity,” “Israel,” “Move,” and “Moondreams,” fine improvised solos by Davis, Konitz, and Mulligan were meaningfully integrated into the arrangers’ scores. Various octets, nonets, and other small ensembles soon followed suit, as did such West Coast-based quartets and quintets as those led by Mulligan, Chet Baker, Shelly Manne, Shorty Rogers, Jimmy Giuffre, and Chico Hamilton.
https://www.britannica.com/art/jazz/Jazz-at-the-crossroads#ref395994
