Mumford & Sons front-man Marcus Mumford and Justin Timberlake worked together on the soundtrack for Inside Llewyn Davis, a Coen Brothers film which stars Timberlake and Mumford's wife Carey Mulligan.

Timberlake revealed the movie was coming in an interview with Capital FM.  He then added that the soundtrack would include the interesting collaboration:

"I did work with Marcus Mumford on the soundtrack, so I became very good friends with them.  Marcus and myself, we all kind of worked on the music together and I don't know any other world where we would have the opportunity to collaborate like that but it was so much fun."

Mumford recently joked that he'd like to try rapping.  Timberlake recently worked with Jay-Z.