SOB X RBE may be one of rap's most exciting new rap crews, but the Vallejo, Calif. group has been making noise for years. The foursome's first big moment came in 2016, with the release of its breakout single "Anti." But SOB x RBE—made up of Yhung TO, Slimmy B, DaBoii and Lul G—landed its biggest hit to date earlier this year, when Kendrick Lamar personally put the word out that he wanted to work with the Cali collective.

The product of that first-time collaboration is "Paramedic!" a standout song packed with Bay Area bounce that appears on the star-studded Black Panther soundtrack. Slimmy B says Kendrick's camp reached out via social media. "Dave Free, one of Kendrick partners, hit me on Twitter saying that Kendrick wanted us on a track," he tells XXL. "At first we didn't know it was gonna be 'Paramedic!' or be on the Black Panther soundtrack."

Kendrick flew SOB x RBE (an acronym for Strictly Only Brothers, Real Boi Entertainment) out to L.A. and greeted the group with a skeleton of what would eventually become "Paramedic!" "He already had the beat and the beginning part—when he first spit bars on there—that's all he had," Slimmy B says, adding that it took them an hour to finish their parts. "We did all our verses, he put all his magic in there, and sent it back to us."

While thankful to appear on the soundtrack to one of the most successful films of 2018, DaBoii expected a little more out of the experience. "It was cool, [but] we really thought it was gonna be on the movie for real," he says, adding that they re-recorded a clean version of the track for that purpose. "It ended up not making the movie, but shit, we were feeling good because it was on the soundtrack anyway."

SOB has been on the rise in 2018. The group released its sophomore album Gangin in February and hit the road to tour with Post Malone last week. They attribute their meteoric rise to their belief in each other. "We really spoke that shit into existence, but we didn't expect for it to take off as fast as it did," DaBoii admits. "We worked together, and now we successful."

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