According to his manager, Justin Beiber has become a man — vocally.
But his manager, Scooter Braun, has a different way of saying that.
"Vocally, his balls have dropped," Scooter tells Billboard.
With his deeper voice, Justin found it a challenge to sing the "All I Want for Christmas Is You" duet with Mariah Carey.
"That was the hardest song to do," Scooter explains. "A year ago that would have been no problem."
"Yes, that was high," Justin agrees. "But I grinded it out and we got it down."
The duet has already hit the Web. How do you think Justin did? Listen here on YouTube!