Fans were shocked during J. Cole’s set at Chicago’s Spark in the Park 2014 when the North Carolina MC brought out Chance the Rapper last Thursday (Sept. 4). Taking over the stage, the two let loose their new surprise-collab during the live performance. Pacing back-and-fourth, Chance kicks off a few rhymes for “Thotty.”

The Chicago MC originally previewed the track on Tony Touch’s show but cut the snippet short. Watch the two perform “Thotty” above and stay tuned for the official release.