"That's her style," he said. "Even if she's in the spotlight, it really doesn't matter what people think."
The Rihanna gig caps a successful year for the rapper, who will release his first album this year.
Born Jermaine Cole, the rapper has been releasing mix tapes since 2007, slowly building his celebrity and opening gigs. Jay-Z came first, and later Drake, for whom he opened on the rapper's recent European tour.
He said opening for someone with an established fan base comes with pressure.
"I'm used to doing hourlong sets in front of 600 to 3,000 people, but when I'm opening for one of these guys, it's a total change of pace. Mentally, I have to prepare myself," he said. "On the flipside, it's when I learn the most as a performer. I don't have the upper hand. I have to work harder. I have to adjust. Night after night, it's a learning experience."
He got the Rihanna job thanks to a recording accident. He'd met the singer a year and a half ago at the Grammys and was a fan.
"I'm a fan of her edginess," he said.
Though he'd been commissioned to do a hip-hop remix of "S&M," he instead accidentally ended up rapping on the song's dance version. Still, when it was leaked in January, his remix was a hit with the singer's fans, and he was asked to open on the Loud tour, where Cee-Lo Green is a co-headliner.
Like the opening gigs he's done before, his 25-minute set at 1st Mariner is more suited to the headliners' fans and will play up the pop undertones in his raps.
Thankfully, he said, he'll soon get to play his own music.
His first single will drop "any day now," as long as it's cleared to sample Kanye West and "a huge urban pop record from the '80s." And his first album, untitled so far, could be here as soon as August.
J. Cole opens Saturday for Rihanna at 1st Mariner Arena, 201 W. Baltimore St. Doors open at 7:30 p.m. Tickets start at $28.95. Call 410-547-7328 or go to ticketmaster.com