Justin Bieber Covers The Beatles During Mentoring Stint on 'The X Factor (US)'

Photo credit: Daniel Tanner/WENN

Justin Bieber shows off his pipes when visiting "The X Factor (US)" to mentor the contestants. The 18-year-old Canadian helps judge L.A. Reid to coach a group of aspiring singers. While doing so, he takes time to play a piano and sings The Beatles' "Let It Be".

Sharing some insight into his success, 18-year-old Bieber tells the contestants all of whom are older than him, "They told me that I was too young." He adds, "You know, you're never too old or too young. If you have the voice and the talent, nothing's impossible."

Earlier on Twitter, Bieber was irritated by some people who called his stint on the singing competition a rating ploy. "Heard we got used for ratings according to twitter and we arent even on until tomorrow?" he tweeted. "@xfactorusa could of just told us."

While Reid has Bieber as his assistant, Britney Spears is helped by will.i.am, Demi Lovato is assisted by her Disney friend Nick Jonas, and Simon Cowell gets a helping hand from Marc Anthony.