Carrie Underwood, Demi Lovato, Luke Bryan and More Ring in 2016 in Times Square for 'New Year's Rockin' Eve'

Carrie Underwood
Taylor Hill/Getty Images

Carrie Underwood performs during Dick Clark's New Year's Rockin' Eve at Times Square on December 31, 2015 in New York City. 

It was an American Idol reunion as Carrie Underwood rang in the New Year in New York City's Times Square as part of the lineup on ABC's Dick Clark's New Year's Rockin' Eve with Ryan Seacrest.

Underwood, who rehearsed with her band earlier in the evening prior to when the famed New Year's Eve Waterford crystal ball was raised at 5:45 p.m., was introduced by old friend and host Ryan Seacrest just before her NYE set. 

The country star was a classy vision in emerald as she strapped on a white acoustic guitar and performed a medley of hits "Smoke Break," "Heartbeat," and "Before He Cheats."  

The 32-year old singer -- who snapped a selfie with the  crowd -- didn't have much time at the end of her set to take it all in. As soon as she wrapped, she was whisked through the crowd to join Seacrest along with NYE performers Charlie Puth, Wiz Khalifa, Demi Lovato and Luke Bryan to count down to midnight.

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Over a million revelers -- many of whom arrived as early as 8 a.m. on Thursday morning -- were packed into penned areas in Times Square, many waving purple balloons and donning hats provided by Planet Fitness. Every hour on the hour, the crowd practiced the countdown until it was time for the real thing.

Puth, a native of Rumson, N.J., tells Billboard he was overwhelmed by the audience reaction to his hit, "See You Again," which spent 12 weeks at No. 1 on the Billboard Hot 100.  The song, written in tribute to the late Paul Walker, struck a nerve in 2015, and inspired an emotional sing-along with the New York crowd.

"I didn’t realize how many people there were until I looked over yonder and saw all of the people going all the way to 59th street," he told Billboard after his performance with Khalifa, who looked cool in sunglasses and later dropped an F-bomb in an interview with Seacrest on live television. "That’s a long stretch. I think that is the most amount of eyes that me and Wiz ever had on us ever.”

Puth's debut album, Nine Track Mind, is set to drop on Jan. 29, and the 24-year old singer's 2016 is already off to a great start with Grammy and Golden Globe nominations.

Taylor Hill/Getty Images
Charlie Puth and Wiz Khalifa perform during Dick Clark's New Year's Rockin' Eve at Times Square on December 31, 2015 in New York City. 

"I used to sit on those red steps in Times Square," he said. "After a day of getting rejected by all of these record labels I would sit on there and hope that things would work out for me, and we’re off to a great start."

Puth could have another milestone in a few short weeks: The nominations for the Oscars will be announced on Jan. 14. "That would be incredible," he said. 

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Country star Luke Bryan, who rocked with a melody of his hits "Move" and "That's My Kind of Night," said performing on NYRE was a big highlight of 2015.

"This is my kind of night," he told Billboard. "It was awesome. I never would have imagined I would have had the opportunity to play here so definitely a bucket list experience."

As for resolutions, Bryan -- who hits the road again starting Jan. 22 -- is all about family.

"My resolutions are always trying to be a better person, and to love and support the people who support me and be a better dad, a better husband, a better friend," he said.

Lovato's set of "Cool for the Summer" and "Confident" had the crowd pumped as she took the stage after 9:30 p.m. The singer, who was introduced by co-host Jenny McCarthy, looked fierce in a beaded sequined leotard, fur coat and boots as she attacked the stage and whipped Times Square into a frenzy. Lovato's boyfriend, actor Wilmer Valderrama, hung out by the right of the stage, snapping a few photos and chilling out in the audience.

Taylor Hill/Getty Images
Demi Lovato performs during Dick Clark's New Year's Rockin' Eve at Times Square on December 31, 2015 in New York City. 

Backed by a tight horn section on "Confident," her set, which included steam and a shower of confetti, fit the New Year's Rockin' Eve" bill, and was a great preview of her Future Now tour, set to kick off this summer.

After her performance, the singer walked back through the crowd and stopped to take pictures with members of the New York City Police Department and fans along the way.

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Also on hand for the festivities, Mayor Bill De Blasio, who watched Underwood perform before he took the stage to push the button beginning the ball drop, Miss America winner Betty Cantrell, Vanilla Ice, Jessie J (who sang a stunning version of "Imagine," which is always performed in Times Square right before midnight) and Donnie Wahlberg, who was on hand to kiss wife McCarthy at midnight as fireworks illuminated the night sky and confetti filled the air.

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