Sources have suggested that American Idol bosses have changed this week’s theme from Teen Idols to number one Billboard hits.

The celebrity mentor has not yet been confirmed but Fred Bronson, author of The Billboard Book of #1 Hits, has been acting as a Billboard expert for the team. He tweeted:

Just got home from a production shoot. What was I doing? Watch American Idol Tuesday night and find out.

Fred Bronson has worked on idol during previous seasons and is thought to discuss the American charts with the hopefuls.

MJs Big Blog also said that this week’s mentor was a surprise to the contestants and that they didn’t know who they were until they were introduced. Ohhh the intrigue!