While there's a ton of great stuff here by some of the most legendary artists of the 20th century -- and Johnny Cash continued into the 21st century, as well -- there are far too few "hits" here for this double-disc collection to be definitive. There were jukebox hits, like those for Howlin' Wolf, there were regional and national smashes, too, but not one tune from Elvis Presley's Sun sessions is here, despite the fact that all the producers needed to do was license the material from an all too willing Sony/BMG. That said, there is a great wealth of actual Sun material here that is not often heard, with tracks by Bill Justis, Rufus Thomas, Charlie Rich and Charlie Feathers, and many others. If you are looking for some tremendous American roots music recorded by Sun in Memphis, this is a terrific collection to own, but it is far from being the only one that matters.