Over the past several years the contestants on "American Idol" have met many of the major players in the music industry. Last year Gwen Stefani and Jennifer Lopez dropped by to mentor the contestants. This year two more powerful ladies, as well as two influential men, are set to drop by and teach the contestants a thing or two.

On the ladies end, Mariah Carey and Dolly Parton have both signed on to mentor the contestants in the coming weeks. Parton, a top selling country artist for decades, recently released a new album and Carey is one of the top selling artists in history.

The contestants will also get the chance to work it out with Neil Diamond and British composer Andrew Lloyd Webber, who has written many famous musicals including "Phantom of the Opera."

The mentors will spend time with the Idol hopefuls, coaching them and leading them through their song choice. Viewers at home will get to see clips of the mentors helping the singers as well as hear the famous musicians sing on elimination night.