“Relative to the garage-rock outfits with whom they were compared to in the first part of this decade, the Black Keys have more or less stuck with their thing: austerely nostalgic, drums-and-guitar-in-a-dying-industrial-city blues-rock. Singer-guitarist Dan Auerbach and drummer Patrick Carney have managed to forge a career and five albums out of variations-on-a-theme riffs and stripped-for-parts gr”