Jack Black Sings His Rockin' Version of 'Carol of the Bells,' on Video

Jack Black's fully in the holiday spirit ... rattling off a Christmas carol for us in his typical hard-rocking voice in New York City!

We caught up with the actor and singer outside "The Drew Barrymore Show" Tuesday ... and we asked him what his least favorite holiday tradition is.

Either Jack didn't hear us, or he chose to stay positive and give us one of his favorites instead ... because he launches into the song with his usual enthusiasm and projection.

Listen to the song for yourself ... JB doesn't know all the words, but that doesn't stop him from barreling right on through -- before telling us he just loves that track.

Black then heads for the waiting black SUV on the New York City street ... posing like a model with a final look over his shoulder before hopping in the car.

Fans can celebrate Christmas Day with Jack Black, BTW ... or, at least they can see him on the big screen -- because his comedy "Anaconda" costarring Paul Rudd, is due out on the 25th.