George Michael - Singer/Songwriter
A source has revealed that the big surprise guest performer during the American Idol finale tonight will be George Michael. Earlier this week, producer Nigel Lythgoe refused to reveal who the artist would be, only saying that the "biggest star in the world" was coming to Idol.

A representative for Idol would not confirm Michael's appearance, while a representative for George Michael could not be immediately reached.

The season finale of "American Idol" airs live from the NOKIA Theatre L.A. LIVE on Wednesday May 21, (8:00-10:00 PM ET live/PT tape-delayed) on FOX.