Bennett was a confirmed performer at the festival in Montreal. Already in town for an ArtRave concert in Montreal yesterday (July 2), Gaga decided to take the stage with Bennett to perform several songs off their upcoming jazz collaboration release Cheek to Cheek.

The music, off an oft-delayed album that's purportedly coming later this year, certainly fit in well both in the festival's wheelhouse and in Bennett's. Meanwhile, for Gaga, jazz may not be the first genre that comes to mind when thinking of the pop star, but the shoe fits fairly snugly on the just-debuted tracks.