The Miles Davis Quintet underwent innumerable lineup and personnel changes during the decade and a half they were active, but most jazz scholars agree that one of his greatest configurations was his "Second Great Quintet", an astounding lineup which featured Wayne Shorter on saxophone, Herbie Hancock on piano, Ron Carter on bass, Tony Williams on drums, and of course Davis himself. In 1966, Davis released the album Miles Smiles on Columbia Records, which would be the second of five albums he’d record with this configuration, and is now considered one of his greatest efforts. A jazz traditionalist for much of his career, Miles Smiles astounded critics, who were hard up to categorize the hybrid of bop and free jazz that his quintet had put forth, which was full of free-roaming improvisation, eccentric time signatures, and progressive modal and chordal harmonies. Nonetheless it was widely praised for its instrumental mastery, its innovative compositions, and the chemistry between the band members.