American Idol may have dumped its previously-announced "Teen Idols" theme for this week's Top 11 performance round, however it has tapped a teen idol to serve as the musical mentor.

Fox has announced that Miley Cyrus will serve as this week's guest mentor for the Top 11 ninth-season finalists when they perform Billboard No. 1 Hits during Tuesday night's live performance episode.

The 17-year-old Hannah Montana star will also perform "When I Look At You" during Wednesday night's live results show.

In addition, Joe Jonas -- who previously served as a guest judge during last summer's ninth-season audition in Dallas -- will perform a duet of "Make a Wave" with fellow Disney Channel star and girlfriend Demi Lovato on the results show.

Following last week's results show, Fox had announced that "Teen Idols" would be the theme for this week's performances.

The Top 11 ninth-season finalists -- Didi Benami, Crystal Bowersox, Lee Dewyze, Andrew Garcia, Casey James, Aaron Kelly, Michael Lynche, Siobhan Magnus, Paige Miles, Katie Stevens and Tim Urban -- will take the stage live on Tuesday night for the performance episode at 8PM ET/PT.

The live results show will air the following night at 9PM ET/PT.
About The Author: Christopher Rocchio
Christopher Rocchio is an entertainment reporter for Reality TV World and has covered the reality TV genre for several years.