Jazz standard and Billy Strayhorn's "Take the 'A' Train" (1941). With the big bands struggling to keep going during World War II, a shift was happening in jazz in favor of smaller groups. Some swing era musicians, such as Louis Jordan, later found popularity in a new kind of music, called "rhythm and blues", that would evolve into rock and roll in the 1950s. Bebop emerged in the early 1940s, with Charlie Parker, Dizzy Gillespie and Thelonious Monk leading the way. It appealed to a more specialized audiences than earlier forms of jazz, with sophisticated harmonies, fast tempos and often virtuoso musicianship.
John Coltrane played together occasionally in the late 1940s. He was a member of groups led by Dizzy Gillespie, Earl Bostic, and Johnny Hodges in the early to mid-1950s. In the summer of 1955, Coltrane was freelancing in Philadelphia while studying with guitarist Dennis Sandole when he received a call from Davis. The trumpeter, whose success during the late forties had been followed by several years of decline in activity and reputation, due in part to his struggles with heroin, was again active and about to form a quintet. Coltrane was with this edition of the Davis band (known as the "First