NEW YORK — It was a benefit show, sponsored by a soft drink company, in a nonsmoking New York venue, but that didn't stop Kid Cudi from striding onto the stage Saturday (September 12) night, grabbing a smoke from someone in the front row, hitting it, then launching into a positively spacey set while an audience full of fired-up kids lost their collective minds (and a few T-shirts).

If only all benefits were this much fun.

Yes, on Saturday, less than 24 hours before the kickoff of the 2009 MTV Video Music Awards, Cudi and French pop aesthetes Phoenix brought the party to Terminal 5 for the Pepsi-sponsored Night of Refreshing Music, which benefitted LIFEbeat, the music industry's AIDS education and prevention organization.

There appeared to have been plenty of pre-partying going on (as evidenced by the kids security tossed out before the show even started), and very few people obeyed the smoking laws, which meant that by the time the hotly tipped Cleveland MC took the stage, things were already pretty loose. And his performance definitely sent things over the edge.

Paying no attention to set times and fighting off myriad technical problems, Cudi bobbed and weaved through a set that drew heavily from his upcoming Man on the Moon: The End of Day album — which leaked last week, leading Cudi to joke, "My album's on the Internet right now, so y'all can download it. But make sure to buy it Tuesday, don't f--- around" — as well as his ever-growing list of mixtapes and his handful of high-profile guest appearances.

He bumped through stuff like "Already Home" (from Jay-Z's The Blueprint III) and "Dat New New" (off his Stoner Charm mixtape) with laconic grace, slapping fives with the kids in the crowd and removing his leather jacket to reveal a seriously shiny Jesus piece. He got goofy on party-starters like the disco-flirting "Enter Galactic" and the throwback "Embrace the Martian," and he nearly brought the house down with a half-a-cappella/half-booming take on his breakthrough hit "Day 'n' Nite."

But there were also more sober moments, like when he performed the dark "Solo Dolo" while bathed in a single spotlight, or on the genuinely great "Soundtrack to My Life," a somber tune that samples the ethereal noise of Icelandic group Múm and features Cudi rapping about his splintered childhood while the noise grows around him and he tosses his mic stand to the ground and shouts to his demons, "I got the last laugh."

It was a performance that showed off Cudi's range as a performer, and it justified the "next big thing" hype that surrounds him these days. And just when things were threatening to get a bit too heavy, Phoenix took the stage, looking fabulously, fashionably tousled and ripped through a lightning-quick set of pitch-perfect pop from this year's Wolfgang Amadeus Phoenix album ("Listzomania," "Lasso," "1901") and their earlier albums ("Run, Run, Run," "Too Young," "Long Distance Call"). The crowd greeted them with glee, dancing, shouting and snapping about a bajillion camera-phone pics. Phoenix looked genuinely amazed.

It was a pretty neat capper to a pretty sloppy, sweaty, smoky, all-ages affair — you know, how all benefits probably should be.

Watch the 2009 MTV Video Music Awards Preshow this Sunday, September 13, at 8 p.m. ET, followed by the big event, live at 9 p.m. Check out our interactive map of New York to see how the city is celebrating the VMAs all week long, and stay tuned for party coverage, concert reports, behind-the-scenes updates and more.