This past December, Windy City representatives Mike Schpitz and Slot-A came together with The DJBooth to drop their debut collaborative full-length. As longtime fans already know, though, that set was just the latest product of a relationship that goes way back. That is to say, the duo have quite a bit of collaborative work behind them. Case point: Big Ol Butt, an unreleased joint recorded circa 2009. Making its world premiere on our pages, the record finds Mike adopting a flow reminiscent of fellow booty fiend Slick Rick as he pays tribute to a few of his favorite asses in the (late-2000s) industry—including MIA, Santigold and Kid Sister. Slot-A backs his partner's anatomically-preoccupied bars with a head-noddable mix of thumping percussion and grainy synth-bass. Feeling it? This joint isn't attached to a larger project, but you can find plenty more dope material from the Chi-town twosome on Have You Seen My Stapler?, still available free of charge right here in the Booth.