From CD to celluloid: Pop stars with a second string

Why stick to the day job? Justin Timberlake, and Marcus Mumford of Brit Award-winning folk band Mumford and Sons have collaborated on the soundtrack of the new Coen brothers film, Inside Llewyn Davis, out later this year. Timberlake appears in the film – inspired by the New York folk-singer Dave Van Ronk – along with Mumford's wife, Carey Mulligan, which might explain the unlikely pop/folk pairing of the duo on the soundtrack – although Mumford is a fan of the 1960s folk icon. Timberlake, who also wrote the soundtrack for the forthcoming film The Devil and the Deep Blue Sea, which stars his wife, Jessica Biel, said: “I don't know any other world where we would have the opportunity to collaborate like that but it was so much fun.” He added that he became “very good friends” with Mulligan and Mumford.

The duo are not alone in their quest to branch out musically from making records – just look at Radiohead's Jonny Greenwood, whose latest film venture was the soundtrack for Paul Thomas Anderson's film The Master. Musicians are looking for new ways to supplement their incomes, especially now that record sales have dropped – so working on film and TV soundtracks is a new way of earning cash and publicity.

Sometimes it's more of an honour as in the case of singer Emeli Sandé, who has just co-written and performed the emotive pop song “Here It Comes” for Danny Boyle's new art-world thriller, Trance, out later this month. Although it's unlikely this song will follow in the footsteps of Adele's Oscar and Brit Award-winning Bond theme tune song “Skyfall”, Sandé believes she has “created something very special” with Underworld's Rick Smith, who has written the new film's entire original score, which stars James McAvoy, Rosario Dawson and Vincent Cassel.

Sandé sang the hymn “Abide With Me” at the London Olympics opening ceremony last year, when Boyle was artistic director and Smith was musical director.

The new Tom Cruise movie, Oblivion, out in April, has been scored by M83's Anthony Gonzalez with TRON: Uprising score composer Joseph Trapanese. This is a soundtrack debut for Gonzalez's French electronic/shoegaze band from Antibes, whose rousing synth sounds combined with sweeping orchestral elements can be heard throughout the film, and in the end-title track “StarWaves” by Gonzalez and featuring Norwegian singer Susanne Sundfor. Gonzalez was approached by the film's director, Joseph Kos-inski, who thought M83 would make a great match for this big, Hollywood, sci-fi epic story.

“I've wanted to do soundtracks for so long,” said Gonzalez. “Starting with such an ambitious project, especially in the sci-fi category, means a lot to me.”

The American indie band The Hold Steady (pictured) have just recorded a version of the song “The Bear With the Maiden Fair” for the third series of his US hit TV show Game of Thrones, with the lyrics written by Game of Thrones author George RR Martin and music by composer Ramin Djawadi. It may sound better suited to the fantasy saga rather than in the charts, but it will be released on seven-inch vinyl on Record Store Day on 20 April.

“We were honoured to be asked to record a song for Game of Thrones,” Hold Steady singer-guitarist Craig Finn tells me. “The pairing of our music and the show has gotten a lot of positive feedback and anticipation from our fan base as well as media attention. ”

Guy Garvey of Elbow is doing something a little more different too. He has just been out in New York working on the score for a new King Kong musical with Massive Attack's Robert Del Naja, focusing on the character Jack Driscoll, the first mate on the ship that sails off to find the gorilla. Garvey has written three songs for the epic musical, which previews in Melbourne, Australia, in May, according to kingkongliveonstage.com, before it embarks on an international tour in June, featuring a one-tonne, six-metre-high animatronic silverback gorilla puppet. Garvey said: “It couldn't be more different than what I do with Elbow.” His trip to New York also inspired a song for Elbow's upcoming new album which is due out next year – the song's working title is “New York Morning”.

Maybe for these pop stars, a change is as good as a rest.