After the sleek, commercial sound of El Camino, the Black Keys return to a more soulful groove on the new Turn Blue. Produced again by Danger Mouse of Broken Bells, the former Ohioans float through some nifty psych on the record. Two word review: Brothers Bells. It's mellower, for certain, but lest you think that won't fare well inside a stadium, there is a fresh spritz of Pink Floyd to the affair, and they did just fine in arenas. Kentucky's Cage the Elephant opens with its modern garage-rock melange of Strokes, Pixies and Black Lips influences.