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
Horn in jazz compete directly with Basie's hard-swinging blues, the duo capitalized on their contrast from Basie’s sound, playing with a soft and mellow sound. By showcasing their different sound, Ruff and Mitchell continued to get bookings from Birdland to play intermission for other big name groups like Miles Davis, Dizzy Gillespie, Sarah Vaughan, Lester Young, Dinah Washington and others. After working with Claude Thornhill and arranging for his orchestra, he began arranging for Miles Davis. In 1948 the Miles Davis Nonet was formed with a sound completely unlike anything jazz listeners had heard before. The original idea for the nonet was to