The reunited Guided By Voices performed "The Unsinkable Fats Domino" last night on Late Show With David Letterman. The song, which is from their new album Let's Go Eat the Factory, may or may not be about the enduring power of rock & roll; the band itself, which formed in 1983, has been around the block more than once. After an energetic performance marked by an unscripted tumble, Letterman seemed comically concerned with the health and safety of the band. "You all right?" he asked, joking, "Don't even think about calling OSHA."