The Black Keys continued their whirlwind week of celebrating the release of their latest album, El Camino, with a visit to the set of The Late Show With David Letterman last night. Augmented by a second guitarist and a keyboard player, the power duo of Dan Auerbach and Patrick Carney stomped through the track, much to Letterman's delight. "Akron is happening!" exclaimed the host when he stepped onstage to greet the band.