R. Kelly was a surprise addition to the Saturday (13Apr13) line-up of California's Coachella festival when he joined French rockers Phoenix onstage during their set.

The indie rock band played a hits-packed gig as they drew the day to a close, and they thrilled the audience in Indio with a special star performer.

Kelly came onstage to join Phoenix for a mash-up of his 2003 single Ignition (Remix) with Phoenix's hit 1901.

It was a day of surprise collaborations - John Legend performed with Italian Dj/producer Benny Benassi, and British band The xx teamed up with Solange Knowles for a cover of Aaliyah's Hot Like Fire.

Lead singer Romy Madley Croft told the crowd, "It really is a dream come true to be playing the main stage."

Other acts appearing on Saturday's bill included folk star Ben Howard, The Postal Service, Bat for Lashes, Hot Chip and Harlem Shake hitmaker Baauer.