1940s in jazz of the time initially met with a divided, sometimes hostile response among fans and fellow musicians, especially established swing players, who bristled at the new harmonic sounds. To hostile critics, bebop seemed to be filled with "racing, nervous phrases". Despite the initial friction, by the 1950s bebop had become an accepted part of the jazz vocabulary. The most influential bebop musicians included saxophonist Charlie Parker, pianists Bud Powell and Thelonious Monk, trumpeters Dizzy Gillespie and Clifford Brown, and drummer Max Roach. The swing era lasted until the mid-1940s, and produced popular tunes such as Duke Ellington's "Cotton Tail" (1940) and
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