Cool Jazz evolved directly from bop in the late '40s and '50s. Essentially, it was a mixture of bop with certain aspects of swing that had been overlooked or temporarily discarded. Dissonances were smoothed out, tones were softened, arrangements became important again, and the rhythm section's accents were less jarring.

Cool Jazz evolved directly from bop in the late '40s and '50s. Essentially, it was a mixture of bop with certain aspects of swing that had been overlooked or temporarily discarded. Dissonances were smoothed out, tones were softened, arrangements became important again, and the rhythm section's accents were less jarring. Because some of the key pacesetters of the style (many of whom were studio musicians) were centered in Los Angeles, it was nicknamed "West Coast jazz." Some of the recordings were experimental in nature (hinting at classical music) and some overarranged sessions were bland, but in general this was a viable and popular style. By the late '50s, hard bop from the East Coast had succeeded cool jazz, although many of the style's top players had long and productive careers. Among the many top artists who were important in the development of cool jazz were Lester Young, Miles Davis, Gerry Mulligan, Stan Getz, Shorty Rogers, and Howard Rumsey (leader of the Lighthouse All-Stars). ~ Scott Yanow