As emphatically as it shatters your pre-conceptions about what four BRIT School graduates should sound like, black midi’s astonishing debut dismantles any hoary old notions of genre boundaries, song structure and what’s possible for a basic guitars-and-rhythm-section set-up. From the scratchy, frantic start (“953”) this is an album that invites whiplash with its frequent sharp turns. It’s a dizzying, freeform tapestry of sounds and ideas, driven by Morgan Simpson’s heroically fluid drumming and topped by Geordie Greep’s inscrutable, affected croon. At the album’s midpoint, after the Londoners’ have bent jazz, math-rock, punk and psychedelia to their singular will, calm descends with a gentle, bucolic strum on “Western”. It lasts less than two minutes before a skronk of noise arrives like thunder cracking through a peaceful summer’s afternoon. Even after repeated listens, nothing here is predictable or expected. And that’s what makes Schlagenheim so exhilarating.