B.o.B, Paramore And Bruno Mars' VMA Medley: Making The Show

MTV News was in the rehearsal for the collaboration — and for B.o.B and Hayley Williams' first meeting.

LOS ANGELES — [artist id="3238990"]B.o.B[/artist], [artist id="3528710"]Bruno Mars,[/artist] and [artist id="1968732"]Paramore[/artist] could teach a class in chemistry. The three acts blended together like they were one touring group during their medley performance of "Nothin' on You," "Airplanes" and "The Only Exception" at the 2010 MTV Video Music Awards on Sunday night.

It was the first time that the artists all came together in one setting, but during their rehearsal over the weekend, B.o.B, Mars and Paramore singer Hayley Williams were playful and relaxed, which certainly helped set the tone for the big night.

B.o.B and Mars' sweet "Nothin' on You" served as a dramatic introduction to Sunday's performance, but when the pair rehearsed the number the day before, they were having plenty of fun, as they took turns trying to upstage each other with covers of songs by Drake and the Notorious B.I.G. Between takes, they also dished out a Jeffrey Osborne-like rendition of "Nothin'."

Mars began singing the tune in a low register, and B.o.B followed suit before the duo broke out laughing. The good vibes bled into the next portion as well.

"Where are you guys?" Williams could be heard asking over her microphone. Although she was onstage with Mars and B.o.B, they were in the foreground and her view of them was obstructed by a pillar. Upon hearing her, B.o.B proceeded to make a beeline over to the Paramore frontwoman.

Williams and B.o.B scored a top-five hit with "Airplanes," and the track's video earned multiple VMA nods, but the two had never physically worked with each other until the rehearsal. "We finally met for the first time," B.o.B told MTV News on Saturday, turning to the camera excitedly, after hugging Williams. "I hope I don't mess up."

"I'm gonna trip and fall," Williams responded about their big performance. "Catch me, please!"

Nobody fell, obviously, and the trio lifted one another up during the soaring medley, which was one of the night's highlights.

The Moonmen have all been handed out and the stars have gone home, but there's plenty of 2010 MTV Video Music Awards news, interviews, behind-the-scenes scoop, party reports and more still to come, so keep it locked on MTVNews.com.