If you're still reeling over the Mos Def and Talib Kweli’s decision to reunite as Black Star, but haven't had the chance to catch them live, then their appearance on last night's Late Night with Jimmy Fallon will definitely be a treat. The duo performed two tracks, "You Already Knew" and "Little Brother," with their friends and Fallon house band, The Roots. It was a laid back affair—Tyler, the Creator did not return Mos' favor and yell, "SWAG, SWAG" at the camera when their performance was finished.