The ever-shifting sands of rap album release schedules can’t conceal a real event. For all its botched marketplace delivery, this pithily captivating and ruthlessly introspective third (if you count his debut mixtape) full-length epistle from the twisted mind of still-only-21-year-old west coast microphone tyro Sweatshirt is no less of a hip-hop landmark than higher-profile recent communiques from Drake and Kendrick Lamar. From Huey’s deceptively jaunty lounge organ to the ominous piano which haunts Off Top, Thebe Neruda Kgositsile (as his mum knows him) has as intuitive a grasp of how to punctuate a thought process with musical trigger points as any rapper in history.