The Coen Brothers are planning another musical film as one of their next projects.

The pair will follow-up Inside Llewyn Davis with a film set in the world of opera, Digital Spy reveals citing Vulture.

"I think this is kind of as close to a full-blown musical as we would make," they said of Llewyn Davis. "Certainly, there's as much music in this movie as in any full-blown musical.

"Perhaps less dancing. But one of the two things we're writing right now, it's not a musical per se, but it has what might be considered more traditional musical numbers. It's a musical comedy."

Oscar Isaac, Justin Timberlake and Carey Mulligan feature in the new movie, which centres around a struggling musician living in Greenwich Village in the '60s.

Inside Llewyn Davis will receive a limited U.S. release on December 6 before its full release on December 20. It will debut in the UK on January 24.