Usher premiered his new holiday duet with Justin Bieber, The Christmas Song (Chestnuts Roasting on an Open Fire), on Monday's edition of On Air with Ryan Seacrest.

Usher said “it's amazing" to see Justin's continued success, and the dignified manner in which he's doing it.

"Not only how seriously he takes it, but also just how much he loves his fans," the My Boo singer explained of his young protégé. “He is also really growing as an artist ... you can get lost in this, but he is growing.”