The contestants on X Factor judge L.A. Reid's team will be getting a leg up from none other than Justin Bieber, who has signed on to be a celebrity mentor. According to TMZ, Bieber headed over to Hollywood hills to give his best advice to the team of hopefuls L.A. picked from auditions. The other judges - Britney Spears, Demi Lovato, and Simon Cowell - have not yet had their celeb mentors revealed. It's going to be hard to top Bieber, though. The X Factor will premiere on FOX September 12. Photo Credits: © Universal Music Group, Source: Starpulse.com
