'American Idol' gets its twang on tonight, as Dolly Parton will make a guest appearance on the show. The country legend will serve as a guest judge and mentor to the contestants, coaching them through singing some of her biggest hits. She'll return Wednesday night to perform her new song, 'Jesus and Gravity.'

'Idol' alum Phil Stacey will also appear on Wednesday's 'show, in a special segment featuring past contestants who have since moved to Nashville. Stacey writes in his USA Today blog that he is thrilled to share the spotlight with one of his musical heroes.

"Had I known that Dolly was going to be there when I filmed it, I would have told her on my video that I actually took Kendra to Dollywood for our honeymoon! That's right... Dollywood. If there was anyone out there doubting my hillbilly roots, let all questions be laid to rest. I'm a proud country boy! And I love me some Dolly!"

Wednesday night's Nashville segment will also include appearances by 'Idol' alums Bucky Covington and Bo Bice.