Packed into that set of "Who's Gonna Save My Soul" demos and alternate takes is this unreleased Gnarls tune "Mystery Man." It's a b-side collage stitched of a couple sketches -- Cee-Lo soulfully straining to a fat keyboard-and-backbeat vamp, bookended by a pair of Danger Mouse control-room geek-out instrumentals -- so while it's not Gnarls in fully realized pop mode, ...