One Direction rock. Literally. The boys brought the totally rawkin' title track of their new album 'Midnight Memories' to the stage of the season finale of Season 3 of 'X Factor' (Dec. 19), showing off their rock 'n' roll side. It was, as always, flawless.

Harry Styles was rocking a hair tie, Keith Richards-style. We are not sure how we feel about that bit of accessorizing. We do love hearing Niall Horan and Liam Payne bring the rock during their performance, and the screamy vocals were impressive. It's different, new and exciting.

Post-perfect performance, host Mario Lopez queried the band about their holiday plans. "We're going to go home and chill with our families for a little bit, eat lots of food and get really fat," Liam Payne said.

Hazza was asked if he's been naughty or nice. Yes, every single Directioner screamed her head off at that moment.

Of course 1D were doing Simon Cowell the favor by performing on the U.S. version of the show again. While Kelly Rowland, Paulina Rubio and Demi Lovato danced during the song, Si Co sat there with that smug look on his face because, well, he can. This is his doing, and we thank him for it.

Diva Mary J. Blige also brought some holiday cheer with 'Rudolph the Red Nosed Reindeer,' while Lea Michele performed her solo single 'Cannonball' and rocked it. She looked extra sexy in liquid leggings, too. But it was all about that voice and her infectious smile.

Pitbull performed his latest smash 'Timber' sans Kesha. She was there in spirit and on the big video screens.

It was an action-packed finale, for sure!

Watch Mary J. Blige Perform on 'X Factor'

Watch Lea Michele Perform on 'X Factor'

Watch Pitbull Perform on 'X Factor'