From the sound of their eponymous debut, Brighton's Diagonal never heard a record past 1980. Their pastiche of '60s and '70s acid, prog, and jazz-rock is so authentic that it begs the question: why not just listen to the original inspirations? Well, they never had production and chops like this. Diagonal also never succumb to excess. These five tracks total over 46 minutes, but they shapeshift so deftly that they feel much shorter. "Semi-Permeable Men Brain" morphs from a Miles Davis-esque (fusion era) simmer to a swinging, bell-bottomed groove to a bubbling, organ-driven rave-up to a monster percussion break that crate diggers would do well to track down.