Go Behind the Scenes at 'New Year's Rockin' Eve' With Demi Lovato, Luke Bryan and More

Demi Lovato
Taylor Hill/FilmMagic

Demi Lovato performs during the 2015 93.3 FLZ Jingle Ball at Amalie Arena on December 19, 2015 in Tampa, Florida. 

Before Dick Clark’s New Years Rockin' Eve With Ryan Seacrest went live at 8 p.m. (ET), Billboard crashed the party on Luke Bryan, Demi Lovato, and Wiz Khalifa and Charlie Puth.

The country star rehearsed his set earlier today in Times Square, and his two-song medley -- which includes “Move” and “That’s My Kinda Night” -- rocked the stage located at 46th Street. Dressed simply in jeans, a hat and a light colored jacket, the 39-year old singer lead his band in a tight rehearsal. By the second check, Bryan was loose, waving to the fans from the stage and and taking it all in. He even took some time to take a selfie with the crowd in the background.

"Ready to have a big night in New York City?" he called out to the crowd, which answered in screams.

The Leesburg, Georgia native also experienced a "first" on stage -- learning how to tie a scarf to keep warm. That shouldn't be a problem this evening with the low at 37 degrees. 

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Lovato rehearsed early in the afternoon, delivering back to back performances of "Cool for the Summer" and "Confident." Lovato was escorted by her longtime boyfriend, actor Wilmer Valderramma, who posed with members of the New York City Police Department as the famed New Year's Eve Waterford Crystal Ball was raised high above Times Square.

Puth and Khalifa rehearsed "See You Again" shortly before broadcast, and Puth seemed unfazed by the cold. He removed his parka after the first performance, and was all smiles before playing the first notes of the song, which the duo performed amidst a blast of smoke and confetti. Wiz was in good spirits, doing a little shuffle on stage as Taylor Swift's "Bad Blood" filled the air.

The broadcast has something for everyone, according co-host Jenny McCarthy.

“If you’re a country fan, Times Square is the place to be because we’ve got Carrie Underwood and Luke Bryan performing,” McCarthy told Billboard.

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Tonight’s show on ABC is an ambitious lineup with five and a half hours of music and 38 performances. The Times Square lineup includes Underwood, joined by Bryan, Wiz Khalifa and Charlie Puth and Demi Lovato. Fergie will toast the evening on the other coast at the Billboard Hollywood Party, with performances by One Direction, 5 Seconds of Summer, Alessia Cara, Andy Grammer, DNCE, Elle King, Ellie Goulding, Fall Out Boy, Macklemore and Ryan Lewis, Nathan Sykes, Nick Jonas, OMI, Pentatonix, Rachel Platten, Tove Lo, and Walk the Moon.  In addition, Jimmy Buffett is set to wish Parrotheads everywhere a Happy New Year with a special performance live from the Barclays Center in Brooklyn.

The program will also host the world premiere of Taylor Swift’s “Out of the Woods” music video. A teaser of the video was debuted earlier today.