Mad Men star John Hamm and Zach Galifianakis took to the stage at Bonnaroo Festival in Tennessee to lead the crowd in the USA for Africa hit We Are the World as part of an '80s themed "Throwback Superjam Dance Party".
The event, curated by EDM artist Pretty Lights, Metallica bassist Robert Trujilli and DMC of Run-DMC, who performed some Run-DMC hits. Chance the Rapper was also on hand to perform a medley of DJ Jazzy Jeff & The Fresh Prince's "Summertime" and The Notorious B.I.G.'s "Juicy".
Click the link above to watch Hamm and Galifianakis and watch below to see Chance the Rapper's medley.
