Watch Jon Hamm & Zach Galifianakis Sing 'We Are the World' at Bonnaroo 2015 (Video)

Jon Hamm takes the stage with Zach Galifianakis at the 2015 Bonnaroo Music & Arts Festival on Saturday (June 13) in Manchester, Tenn.

The Keeping Up With the Joneses co-stars helped to kick off the Superjam dance party and led the crowd in a rendition of the 1980s hit “We Are the World.”

Watch the video from a concert-goer below!

Meanwhile, Jon and Zach also performed a surprise comedy set at the festival that day.

15+ pictures inside of Jon Hamm and Zach Galifianakis at Bonnaroo…