Power pop outfit Fountains of Wayne are celebrating their 15th year in the business with the release of Sky Full of Holes in August. It’s a radical diversion into Portishead-inspired trip hop territory for Chris Collingwood and his band, who have clearly tired of the chirpy rock they’ve been pedaling for as long as anyone can remember. Except, of course, it’s not. “A Dip in the Ocean” fits perfectly into the group’s Cars-like desire to create infernally catchy songs with just a few chords and a sing-along chorus. “Are those yours?” Letterman asks the drummer at the end, pointing to his kit. “They’re gorgeous.” Proof that national talk show hosts, whose whole job it is to make conversation, clearly run out of things to say sometimes.