Justin Bieber Usher singer leather concert leather jacket Justin Bieber Usher singer leather concert leather jacket

Justin Bieber and Usher performed at the Christmas tree lighting ceremony at the Rockefeller Center in New York City yesterday, and it looks the 17-year-old pop star and his mentor had a blast belting it out. Funny, Usher's career has totally taken a backseat to Bieber's ... think he minds?

Busta Rhymes also joined the guys onstage, and afterwards Bieber tweeted, "that was a great day....HAPPY HOLIDAYS EVERYONE!!". We'll get to see their complete performance when the concert airs next Wednesday ... can't wait!