When Mark Simpson and Quatuor Diotima gave the premiere of Thomas Adès’s Alchymia two years ago, the piece was hailed as one of the composer’s finest recent achievements. Now, on this immaculate EP recording by the same performers, it sounds like some of the best recent chamber music of any composer, full stop.

It begins with music that pulls inexorably downwards – an immediate stab of melancholy that recalls the opening of Adès’s 2005 Violin Concerto. Simpson’s basset clarinet is the highlighted instrument here, his playing careful and delicate, the lines emerging like tendrils growing not towards the sun but down into darkness. In characteristic, paradoxical style, Adès achieves a sense of timelessness precisely by referencing and transforming music of previous eras: the fact that the airy, almost formlessly scurrying second movement is based on Byrd might pass the listener by, but the third movement, entitled Lachrymae in a nod to Dowland, clearly evokes an Elizabethan viol consort. The fourth quotes a melody from Berg’s opera Lulu, a perky street song dissolving into bubbles that break on the music’s surface; the whole thing then somehow slows into a passage of almost Mahlerian emotional intensity. The result is both immediate and intriguing: a 20-minute chamber work with the scope of a symphony.