Source: CoachellaPreviously: Pitchfork Music Festival Announces 2013 Headliners

Over the weekend, Phoenix closed out Saturday's festivities at Coachella. During their set, the band brought R. Kelly on stage as a surprise guest for a mash-up of his classic 'Ignition' with their 2009 single '1901'. On paper, it may look weird, but the songs worked great together live. Check out this performance above.