Kind of Blue Adderley had joined in the fall of 1957, with tenor saxophonist Coltrane returning at the beginning of 1958; pianist Evans had replaced Red Garland in April 1958, but quit in November to be replaced in turn by Kelly; and drummer Cobb had been hired in May 1958. The Davis band played a mixture of pop standards and bebop originals by Charlie Parker, Thelonious Monk, Dizzy Gillespie, and Tadd Dameron. As with all bebop-based jazz, Davis's groups improvised on the chord changes of a given song. Davis was one of many jazz musicians growing dissatisfied with bebop, however, and saw its
Tritone substitution Tritone substitution The tritone substitution is one of the most common chord substitutions found in jazz and was the precursor to more complex substitution patterns like Coltrane changes. Tritone substitutions are sometimes used in improvisation—often to create tension during a solo. Though examples of the tritone substitution, known in the classical world as an augmented sixth chord, can be found extensively in classical music since the Renaissance period, they were not heard until much later in jazz by musicians such as Dizzy Gillespie and Charlie Parker in the 1940s, as well as Duke Ellington, Art Tatum, Coleman Hawkins, Roy Eldridge