8 pm/ET FOX
Save! Idol history was made last week when Simon and Co. used their sole judges' save on Matt Giraud, rescuing the contestant from elimination. Tonight the still-standing Matt joins his six fellow contestants to render songs from the disco genre. (Polyester leisure suits, platform shoes and an overgrowth of chest hair are permitted.) The stakes are high: Because of last week's save, two finalists will be eliminated in tomorrow night's results show. Tomorrow night also features Season 7's David Archuleta performing "A Little Too Not Over You," plus disco luminaries Harry Wayne "KC" Casey (of KC and the Sunshine Band), Thelma Houston and Freda Payne delivering a medley of genre gems.