Naming a new project Coma is a curious decision for Rich Homie Quan. For a while, the warbling Atlanta rapper promised to never stop going in with every new release, but he’s slowed down a bit in recent years. Call it self-awareness: Coma sounds like a rapper emerging from a period of inactivity rejuvenated and ready to reestablish himself. Over crawling keys on “Downgrade,” he’s punchy and defiant, sounding like the Future successor he was always pegged to be. The acoustic trap of “Lies” proves he and Gunna are kindred spirits. But it’s on “Old Quan,” which channels the warm Auto-Tuned blues of his definitive songs, that he rediscovers the form that once made him unstoppable.