Justin, Avril And More Celebrate 'What's Next' At Teen People Concert

Timberlake, Lavigne, Mario, Cam'ron and more, work crowd at

NEW YORK — Hammerstein Ballroom was brimming with teens escaping the rainy, cold night to be warmed up by the sounds of Justin Timberlake, Avril Lavigne, Cam'ron, Dirty Vegas, Mario, Sahara Hotnights, and Sean Paul at a concert in celebration of Teen People's "What's Next," an annual issue honoring up and comers.

Sean Paul kicked the festivities off with "Gimme the Light" as he rocked the set, made up like a city street of yore, with brick walls covered in colorful graffiti. Next, the Swedish female punk group Sahara Hotnights took the stage to perform "Alright, Alright (Here's My Fist, Where's the Fight?)" and "Keep Up the Speed."

Though it's safe to say most people in attendance were waiting for

Timberlake, the crowd bounced to every song and clapped generously after each set.

Mario had to perform "C'mon" and "Just a Friend 2002" over the shrieking of girls in the crowd, though it was plain by his mile-wide grin that he didn't mind. He and his backup dancers came to the end of the catwalk to break it down before Mario said, "I love you, New York," and ran offstage.

Between sets, a screen behind the stage played a couple of music videos, but for the most part, those in attendance just quietly watched as the stage was reset for each performer. Sometimes the set-up seemed to take forever, but host Taryn Manning (see "Britney's Pal, Eminem's Squeeze — Taryn Manning's Been Both") kept the crowd on their toes by popping up in different locations to do her introductions.

Dirty Vegas opened their set with a brief "Hello, New York," and then played "Ghosts," while pockets of kids in the audience let loose their best rave moves. The trio performed an extended, slowed-down version of their hit "Days Go By," though eventually picked up the pace. Warmed up enough to give a surprisingly raucous reception for Cam'ron, the audience did backing vocals for the rapper's abbreviated version of "Oh Boy." Cam'ron next brought out the Diplomats to perform "Hey Ma" for the screaming crowd. The three of them did their synchronized dance number from the end of the video and waved goodnight. The short performance left the crowd wanting more.

And they got it in the form of Avril Lavigne and her band. Wearing a

wife-beater, black cut-off shorts, untied clodhopper boots and a dainty gold necklace, Lavigne opened her set — the longest of the night, clocking in at four songs — with "Sk8er Boi." When she finished the song, she collapsed onto the ground, splayed out for a few seconds before getting up to energetically perform "Losing Grip," "Unwanted," and the fist-pumping anthem "Complicated." The entire audience sang along with every word, while Lavigne alternated between bouncing onstage with the band and crouching down on the catwalk as fans grabbed at her feet. In a true-to-form rock and roll ending, her guitar player threw himself into the drum kit, and the band disappeared offstage when the song was over.

Chris Kirkpatrick relieved Manning of her introduction duty for the final performance of the evening: Justin Timberlake.

The 'NSYNC compadre was met with thunderous applause, even when he joked that Timberlake wasn't going to come out. He told the crowd that instead, he was going to perform his own single, called "You Can't be Justified About Blasting Off into Space Without Paying No Rent, JC"

Shortly after Kirkpatrick left the stage, Timberlake, wearing a blue Pony baseball cap, a blue jacket with the sleeves pushed up and grey pants with a swinging wallet chain, joined the 10-piece band already onstage, taking his place at the end of the catwalk behind a microphone stand.

Slap bass and guitar played though a wah-wah pedal introduced a funked-up, solo version of "Gone."

With fans grabbling at his ankles and pants, the singer made his way back to the main part of the stage to perform the also sorrowful, though more up-tempo, "Cry Me a River."

Five dancers, dressed in all black — the three girls wearing fedoras like Timberlake has been seen sporting recently — joined him midway through the song and stayed onstage to form a cipher around him as he briefly beat-boxed before the finale, "Like I Love You."

Just the sound of the opening guitar riff made the crowd go wild. Timberlake performed the popular single, inspiring some audience members to toss tokens of their affection onstage including a teal hat and a purple bra.

At the end of the song, Timberlake slapped hands with some of the adoring front-row spectators, artfully sidestepped the bra and put on the hat over his own before dropping it and pushing through the double doors onstage that said "What's Next."