A sub-style of Bop, serving as a continuation of the preceding Cool jazz sub-style among predominantly white musicians based in the Los Angeles area in the mid-1950s. Miles Davis’s nonet recordings of 1949–50, collected together under the rubric of the ‘Birth of the Cool’, were particularly influential on the West Coast players. These were less distinguished improvisers than Davis, with the notable exception of Art Pepper, and therefore came to rely on a formulaic approach in which group arrangements tended to be more interesting than individual solos. The style also suffered from its reliance on a small circle of studio musicians (headed by Shorty Rogers), whose appearance in various combinations gave the music a certain sameness. Perhaps its most innovative contributions came in the small group performances involving Shelly Manne (on his album The Three, 1954, Cont.) and Jimmy Guiffre, who while working essentially in a bop-derived idiom, also explored ideas that prefigured some of the more delicate qualities of free jazz. Despite the fact that a few important black-American players, most notably Hampton Hawes, were deeply involved in the style, its consideration raises politically charged issues: it is difficult to disentangle West Coast jazz from the notoriously racist policies of the Hollywood studios, in which environment many of its practitioners worked.

(source: Grove Music Online)