Bruno Mars, B.o.B, Janelle Monae Turn In Throwback Grammy Set

Bruno Mars headed into Grammy night on top, with seven nominations under his belt for his singing and songwriting efforts. He has already scored snaps for his studio work, but on Sunday night, the 25-year-old Doo-Wops & Hooligans crooner showcased his stage skills with fellow promising genre-bending stars B.o.B and Janelle Monáe.

Following a string intro, Mars helmed the keys and gently crooned a softer version of his #1 smash with B.o.B, "Nothin' on You." The ATL hitmaker then took the mic, rocking a dapper old-school look and adding a scholarly touch with a monocle as he sang and rhymed the lyrics. Monáe kept the menswear theme going in a voluminous cape, quietly chiming in at a clear podium as B.o.B turned to croon to her.

Suddenly, a faux mid-century black-and-white broadcast introducing Mars took over the screen, and then the live telecast switched to a retro two-tone look. Mars looked perfectly in place as he belted a slowed-down yet soul-injected version of his own #1 single "Grenade," with B.o.B on the piano. A crew of background singers helped transform the pop hit into a doo-wop effort, complete with a few stuttering dance steps; Mars even got on his knees during the bluesy arrangement in a move that would have made legendary funkateer James Brown proud.

Then Monáe stepped up for her ArchAndroid cut "Cold War" in her trademark button-down shirt-and-slacks outfit. Mars hopped on the drums as the lights flashed, fog rolled in and Monáe added her own vocal pyrotechnics to the mix. The songstress then took the performance from retro to rowdy by sailing into the audience for a brief crowd-surf as B.o.B strummed away on the guitar. The upstart trio's upbeat set scored a standing ovation.

Last year, Mars was floored when he first heard he'd racked up seven nods, but added that scoring accolades isn't even his favorite part of his hitmaking gig.

"The funnest part of our job is that we don't know who we're working with next," Mars told in December about working his songwriting and production crew the Smeezingtons. "We're fans and students of music, and we just love to work with whoever wants to work, whoever wants to write a song. Rock, hip-hop, R&B — we just want to do music. And we're happy just doing that."

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