This four-album set is actually just a repackaging of four albums that are available separately: the classic Birth of the Cool sessions, Cannonball Adderley's 1958 date with Miles Davis as a sideman (Somethin' Else), Miles Davis, Vol. 1, and Miles Davis, Vol. 2. The latter two sets feature three often-overlooked sessions from 1952-1954 that actually are among the earliest hard bop recordings, starring Davis, trombonist J.J. Johnson, tenor man Jimmy Heath, altoist Jackie McLean, pianist Horace Silver, and drummer Art Blakey, among others. All of this music was quite influential and is essential (in one form or another) to all jazz libraries.