Bebop

In the late 1930s, an elite group of Swing-bred instrumentalists based in Harlem began collaborating at after-hours jam sessions, exchanging ideas and seeking a new approach to improvisation. Based on Swing and Pop chord structures ("I Got Rhythm" and "Honeysuckle Rose" being two favorites), their music came to feature heavily chromatic melodies, complex chord changes, and fast tempos that ultimately rendered its sources unrecognizable. Named "Bebop," this technically demanding idiom signaled the end of the Big Band era, the rise of the small combo, and by most definitions the dawn of modern jazz.