AceShowbiz - Sia Furler brought her latest album "This Is Acting" to "American Idol" on Thursday, March 24. The Australian singer/songwriter, who served as a guest mentor for that night's episode, treated viewers to a live performance of "Cheap Thrills".
Covering her face with her signature black-and-white wig which she teamed with a huge blue bow, she stood still on a platform while singing the track, which was originally written for but rejected by Rihanna. She let her three dancers, who wore similar wigs and nude-colored leotards, steal the spotlight.
Sia wasn't the only famous face gracing the "American Idol" stage that night. Former contestants Katharine McPhee and David Cook both returned to the singing show and performed for the judges and huge crowd.
The former, season 5's runner-up, wowed fans with her rendition of "Somewhere Over the Rainbow". Meanwhile, season 7's winner Cook played "Heartbeat", a song off his album "Digital Vein" that came out last September via his own label, Analog Heart Music.