If Gnarls Barkley's debut, "St. Elsewhere," was the sound of Danger Mouse and Cee-Lo Green tinkering around with the creation of their bizarre surf-pop/psychedelic hybrid monster, "The Odd Couple" is the sound of that monster escaping from the lab. It's also about a thousand times darker. Danger Mouse goes from gospel to pop to spooky, often in the same track, and Green sets a new vocal bar on the desolate, acoustic-flavored nightmare ballad "Who Will Save My Soul." Zippy first single "Run" and the vaguely romantic rubber ball "Blind Mary" are the only things here that approach the sonic territory of "Crazy," and there are times when Green's quavering falsetto gets downright evil ("Would-Be Killer," "Open Book"). But it seems that the more comfortable the principals get with Gnarls Barkley, the more haunted Gnarls Barkley gets. And it gets stronger, too. —Jeff Vrabel