Stars Rock Out at SundanceGeorge Pimentel/Getty; Chris Pizzello/APphoto

After hyping their movies during the daylight hours, the stars are taking in Park City’s night life with special one-night-only concerts. On Saturday, Joan Jett hit the stage at Harry O’s to celebrate the release of the music flick The Runaways. In the middle of her 10-song set, Jett whipped the crowd into a frenzy when she pulled Runaways stars Kristen Stewart and Dakota Fanning on stage. At the Cornerstone Entertainment party at the Village at the Yard, actor Patrick Wilson belted out 70s hits by Foreigner and Journey with Rock of Ages star Constantine Maroulis. Performers John Legend and Kelis also entertained the festival crowds with memorable music.