Chris Martin performs at Unbroken party

Rocker Chris Martin entertained guests by performing a short solo set at a party to celebrate Angelina Jolie's new movie Unbroken in California on Sunday (14Dec14).

Bosses at Universal Pictures staged a bash as part of promotional duties for the war drama, and Coldplay frontman Martin took to the stage to add some star quality to the event.

He performed three songs, including Viva la Vida, a version of White Christmas, and his track Miracles, which plays over the closing credits of the film. The song has been tipped to land an Oscar nomination, and Martin risked the wrath of Academy Awards bosses by mounting an early campaign for votes, telling the audience, "Put your vote in! Or don't... I'm not supposed to say that."

According to Variety.com, the movie's director Jolie was forced to sit out the party after being diagnosed with chicken pox last week (ends14Dec14).

Unbroken, which tells the story of Olympian-turned-prisoner-of-war Louis Zamperini, premieres on Monday (15Dec14).