When Austin Post uploaded “White Iverson” to social media in early 2015, he was 19, scrounging for ramen and sleeping in a friend’s closet. Plenty has changed, but Post’s appeal is more or less the same. No matter how platinum the records go, he still has the air of an ordinary guy, a Crocs-and-Bud-Light kid from the suburbs who stumbled backward into fame just by strumming what was in his heart. Post didn’t just look past genre, he broke it down, mixing the dark grandeur of trap with the anthemic release of classic rock and country. His signature tracks—“rockstar,” “Sunflower,” “Congratulations”—were both bleak and beautiful, spaced-out and mainstream, hip-hop but not quite. The bass boomed, the melodies soared, and there was Post in the middle, rap-singing his woes like a lonely prince self-exiled in the castle. At live shows, there were no dancers, no pyrotechnics, just Post, in a baggy football jersey with a cigarette in his hand, bringing 60,000 people into his bedroom: The pop star as moody teen.