Assembling a comprehensive multi-disc Johnny Cash collection is a difficult task for a variety of reasons, not the least of it being the sheer number of records Cash put out in the '60s and '70s. Counting duets, he had over 130 charting singles, which is far too much for the average box set, plus those singles don't necessarily tell the full story of Cash the recording artist, since he was a prolific album artist, as well. Then, there's the sheer variety of what he recorded – rockabilly, folk tunes, tales of gunslingers and Indians, scores of novelty numbers, gospel, Americana kitsch, train songs, pop, and straight-ahead country, he tried it all, giving it all his own unique stamp, distinguished by his booming voice and the distinctive two-step muted rhythm picked out by his guitarist, Luther Perkins.