This five-CD set covers Jimmy Martin's complete recorded output from 1954 until 1974, 20 years and 146 tracks cut primarily for Decca-MCA, with a handful for RCA at the very outset. Disc One covers the early days, from his sides with the Osborne Brothers to his formation of a band of his own -- once Martin gets people like banjo man J.D. Crowe and fiddler Gordon Terry, the sound tightens up and gets smoother, and Martin's singing grows in power and confidence. Disc Two represents Martin and the Sunny Mountain Boys at their peak, at least in the studio -- these tracks display a range of singing, emotion, and restrained instrumental virtuosity that are almost overpowering. By that time, Martin had managed to incorporate the best components of Nashville's "countrypolitan" sound into his bluegrass work, and was reaping rewards both musical and financial. Disc Three is a direct continuation, with a growing body of fare that country-rock bands would later pick up from Martin and others. Disc Four, gets into the middle/late '60s, when Martin's music achieved an incredibly high level of dexterity. His fourth distinct lineup of Sunny Mountain Boys are as good as any but the originals; different, with a more brittle, dexterous approach. This disc is dominated by the 1966 instrumental album Big and Country Music; as it will probably never be issued as a CD, this material alone may justify the purchase of this box. Disc Five goes into the mid-1970s, when Martin had a more obviously smooth and commercial sound than his earlier work -- the music is more sentimental and a little less impressive technically, but still worth hearing. The sound is all high quality, and the essay by Chris Skinker and the discography are impressive in their own right.