Justin Bieber and Pitbull light up the 'DWTS' ballroom

Slideshow posted in Photos | Tuesday, September 25, 2012

21 of 69: The opening number for the night featured all the pro dancers of the season and The Troupe to a medley of 'I Wanna Dance with Somebody/Dance Again,' choreographed by Jason Gilkison on 'Dancing With The Stars: The Results Show' on Tuesday, September 25, 2012. (ABC Photo/ Adam Taylor)