At the same time, a more angular and asymmetrical style of jazz improvisation emerged that came to be known as “bebop.”
World War II brought upheavals to jazz, and all else. Musicians were drafted, gas rationing and new entertainment taxes made it more difficult for bands to sustain tours, and a contractual dispute between their union and the record companies kept most musicians out of the studios. Unable to sustain themselves financially, most of the big bands dissolved, ceding their popularity to vocalists (who could record during the ban, albeit with only choral accompaniment) such as Frank Sinatra, and to the small-group dance music called “rhythm & blues” that was gaining popularity among younger African Americans. At the same time, a more angular and asymmetrical style of jazz improvisation emerged that came to be known as “bebop.”