Despite its simple, drums-and-guitar configuration, the two fellows in the Black Keys are rarely short on ideas. In the past few years, guitarist Dan Auerbach released a solo record, drummer Patrick Carney started a splinter group cleverly called Drummer, and the duo teamed with a coterie of hip-hop legends for the Blacroc album. But with the just-released Brothers, the Akron, Ohio, natives are back playing gritty, blues-based guitar rock, albeit with a few tweaks. Vocalist Auerbach channels an ever-deepening strain of Southern soul, and Carney's grooves owe a debt to his hip-hop education. Lead single "Tighten Up" (not an Archie Bell & the Drells cover, sadly) shows that the band isn't afraid to play pop music. Whistles, tambourines and sharp guitar upstrokes join together to create a repetitious funk groove.