 Despite the greater capacity of compact discs, the running time of each of the volumes is no longer than the limit of vinyl records in the 1970s, from 38 to 45 minutes long.For most cuts, the (45 RPM) single version was included where differing from that found on the artist's original album.Many (not all) tracks were dubbed from the original stereo (or mono) master tapes, and therefore represent the best available version on CD.