American Roots Music

Box sets fall into two categories: too comprehensive or not comprehensive enough. Count this four-disc companion to the PBS music documentary among the latter. Sixty-eight tracks is plenty for an individual act but a mere freshman introduction to American roots music. With limited breadth, the curatorial choices are critical. There's not a false step on the Country and Blues discs, with room for both the obvious (B.B. King, Hank Williams) and the exuberantly obscure (Whistler's Jug Band?). But while the Cajun, Tejano and Native American selections are individually clever, their close proximity emphasizes similarity rather than the genres' diversity.