cool jazz

WordReference Random House Unabridged Dictionary of American English © 2025

cool′ jazz′, 

1. Music, Music and Dance a restrained, fluid modern-jazz style of the 1950s, marked by intricate harmonic structures, de-emphasized dynamics, and carefully controlled phrasing and ensemble playing, often with a slight lagging behind the beat. Also called West Coast jazz. Cf. bop¹, hard bop, modern jazz, progressive jazz. 

• 1945–50

WordReference Random House Unabridged Dictionary of American English © 2025

hard′ bop′, 

1. Music, Music and Dance an aggressive, driving, hot style of modern jazz developed by East Coast musicians in the late 1950s as a rejection of the more relaxed, cool style of West Coast jazz. Cf. bop¹, cool jazz, modern jazz, progressive jazz.