In the late 1940s and 1950s, "cool jazz" music evolved directly from "bop" music.

Fundamentally, cool jazz music incorporates certain features of the "swing" style (which have been ignored or temporarily discarded) into pop music. In cool jazz music, original dissonances are smoothed out, tones are softened, arrangement becomes an important factor again, and the rhythm section becomes less harsh. Because some of the leading pioneers of this style of music, many of them studio artists, were concentrated in Los Angeles, cool jazz received its nickname: West Coast Jazz.

Some of the works of cool jazz music are experimental in nature (suggesting influence from classical music), and although some of the arranged parts of the works sound boring, in general, cool jazz music Music is a popular style with survival vitality.

By the late 1950s, although many of cool jazz's top players had long and productive careers, the "hard bop" music coming from the East Coast Has replaced and inherited the status of Cool Jazz.

Among the many top artists, those who played an important role in the development of "cool jazz" music include: Lester Young, Miles Davis, Gerry Mulligan, Stan Getz, Shorty Rogers and Howard Rumsey (LightHouse All-Stars band leader).