AceShowbiz -

Justin Timberlake has just revealed that he has recorded a duet with Mumford & Sons' frontman Marcus Mumford. The new song is for the soundtrack of his latest movie, "Inside Llewyn Davis" directed by Joel and Ethan Coen, in which he stars along with Mumford's wife Carey Mulligan.

"There's a Coen brothers film coming out soon that I was lucky enough to work with Oscar Isaac and Carey Mulligan," the 32-year-old singer/actor announced. "And coincidentally I did work with Marcus Mumford on the soundtrack, so I became very good friends with them."

The new T-Bone Burnett-produced collaboration features Timberlake, Mumford and progressive bluegrass band The Punch Brothers. "Marcus and myself we all kind of worked on the music together and I don't know any other world where we would get the opportunity to collaborate like that but it was so much fun," JT revealed, hinting "not only will that be a great movie, but the music to it will be fantastic."

The movie, "Inside Llewyn Davis", is a drama film loosely based on the life of '60s folk icon Dave Van Ronk as told through his posthumously published memoir "The Mayor of MacDougal Street" and tells the story of the aspiring singer-songwriter (played by Isaac) at the height of New York's 1960s folk music.