Broadly, "cool" refers to a number of post-war jazz styles employing a more subdued approach than that found in other contemporaneous jazz idioms.[1] As Paul Tanner, Maurice Gerow, and David Megill suggest "the tonal sonorities of these conservative players could be compared to pastel colors, while the solos of [Dizzy] Gillespie and his followers could be compared to fiery red colors."[2] The term "cool" started being applied to this music around 1953, when Capitol Records released the album Classics in Jazz: Cool and Quiet.[3]
Mark C. Gridley, writing for All Music Guide to Jazz, identifies four sub-categories, with considerable overlap, that encompass cool jazz:
"Soft variants of bebop," including the Miles Davis recordings that constitute Birth of the Cool; the complete works of the Modern Jazz Quartet; the output of Gerry Mulligan, especially his work with Chet Baker and Bob Brookmeyer; the music of Stan Kenton's sidemen during the late 1940s through the 1950s; and the works of George Shearing and Stan Getz.[1]
The output of modern players who eschewed bebop in favor of advanced swing era developments, including musicians such as Lennie Tristano, Lee Konitz, and Warne Marsh; Dave Brubeck and Paul Desmond; and performers such as Jimmy Giuffre and Dave Pell who furthered Count Basie and Lester Young's small group music.[1]
Musicians from either of the previous categories who were active in California from the 1940s through the 1960s, developing what came to be known as "West Coast jazz".[1]
"Exploratory music with a subdued effect by Teddy Charles, Chico Hamilton, John LaPorta, and their colleagues during the 1950s."[1]