"Happy Birthday to You" is usually how the song starts out, but for Justin Bieber, it went a little different.
Bieber jumped on the DJ booth to show off his dance moves before he sang himself a birthday tune.
"Happy Birthday to me, Happy Birthday to me, Happy Birthday to me," he sang.
"Happy Birthday" was not the only song on his list as he also sang his track "Wait for A Minute."
As for his cake, he had a replica of a 1965 Lincoln Continental, a recent birthday present.
Bieber reportedly joked with guests as he swapped the "21" emblems and changed his age to "12."
He had so much fun that he tweeted out, "Tonight was one of the best nights ever. Thank you to everyone involved. Thank you."