The latest release from the Johnny Cash archive covers roughly the first half of his career, the 1950s and '60s; most of the music has never been or was seldom heard on record. For music historians, disc one will be fascinating for its insights into Cash's earliest recordings. The 1955 live broadcasts from Memphis radio convey the flavor of their time. Sponsored by a local home improvement store, Cash and the Tennessee Two fill their 15-minute program with songs and advertisements delivered in Cash's already recognizable granite voice. The intimate demos of "I Walk the Line," "Get Rhythm" and other Sun-era songs reveal that Cash laid out the blueprints early and seldom deviated from his design.

Disc two, covering the '60s, is as musically enjoyable as it is historically interesting. It covers his first decade with a major label, Columbia, and reveals the demands by the producers (and possibly his own desire for popularity) to sweeten the mix with saccharine choruses and schmaltzy arrangements. Despite this, Cash often remained true to his idiosyncratic rockabilly sound while embracing aspects of the '60s folk revival. A few of the rarities, especially "Five Minutes to Live" and "The Losing Kind," rate with his best recordings ever.