Chance The Rapper may have dropped out of the Mad Decent Block Party Tour due to exhaustion but that didn’t stop him from putting on an energetic performance last night at Lollapalooza. The 2014 XXL Freshman shocked a packed crowd at Chicago’s annual festival when he brought out legendary R&B singer R. Kelly.

While on stage they gave fans a medley of some Kelly’s hits, including “The World’s Greatest,” “Bump N’ Grind” and “Ignition (Remix).” Check out Chance’s surprise performance with R. Kelly above.

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