Many of these innovative tunes were initially released as singles on 78s, but the achievements of the trumpeter and his collaborators—including arranger Gil Evans and alto saxophonist Lee Konitz—begged to be grouped together as an album. Miles’ concept is concrete: cool jazz played by a midsize group and heavy on low-register brass, including trombone and French horn. Effervescent, bebop-influenced solos (“Move“) collide with contemporary classical harmony (“Moon Dreams”), but thanks to the ensemble's skill, the whole set sounds unified and gorgeous.