Justin Bieber tosses off a loyal cover of the Christmas classic 'Santa Claus Is Coming to Town' on 'Under the Mistletoe,' but he injects the fun song with a little funk. It's a bouncy, upbeat holiday anthem and the teen Bieberfies it!

The Biebs' voice isn't as high as it was when he was 15 and 16 and issued 'My World' and 'My World 2.0.' That was just two years ago, but my, how things have changed! As the singer's own manager recently said to Billboard, the singer's musical "balls have dropped" and he's evolving into more of a man as he sings. He also harmonizes perfectly with a choir of people singing under him.

That said, this version of the holiday favorite is one that his younger fans of both genders will love
to sing along to with while ripping the wrapping paper off of presents or while they are baking cookies with mom to leave for Santa.

The Biebs does offer a little improvisational moment during the song. He drops a spoken word phrase into the mix, saying, "So it's that time of year, where you let all your problems go, and you know, you just shake it, shake it, baby!" He really is turning into an R&B singer as he sheds a little of his teen idol vocal style.

Listen to Justin Bieber 'Santa Claus is Coming to Town'