“I’ve never been to Atlanta,” he admits sheepishly. Barely old enough to be called a millennial, the Brooklyn rapper born Sidney Selby III, 19, cites a more prosaic inspiration: a girl he met on Facebook. “We never met in person,” he says. “She just said she was from ATL, so I was like, ‘All right — I got broads in Atlanta.’ It’s real life, you feel me? I put real-life sh*t in my songs.”