Roots 'n' Blues: the Retrospective presents five hours of music over four discs, covering the traditional recordings made by Columbia Records and its associated labels from 1925 to 1950. As an all-inclusive survey of American roots music, this set is an invaluable library piece and a good reference, but where this collection really stands out is in its presentation. The collection does a better service than the more academic studies by including a variety of styles — including early string band recordings, spirituals, jugbands, blues, cajun and country music, mixing the better known artists with the more obscure — in the end, the diversity makes for good listening as well as a good learning experience.