Ry Cooder, like T-Bone Burnett and Tom Waits, is an American roots musician with an imagination dipped in Beat-inspired weirdness. I, Flathead, the final installment of his "California Trilogy," is a kind of sci-fi tale about Kash Buk and the Klowns, a fictional rockabilly/roadhouse band that also appears in Cooder's novella of the same name. None of this really matters, though. If you dig quirky American rock and roll with a dash of Doug Sahm's Tex-Mex pep, guzzle this brew right now.