After almost 20 years of Limelight reviews, I have to confess that this was one of most confronting (to resort to a currently overused term) and occasionally harrowing.

Shostakovich composed 15 string quartets (one less than Beethoven) and much other chamber music. Whereas he composed his First Symphony in 1925 (a work which quickly attained international acclaim and unleashed a torrent of creative exuberance and optimism about the future of the new Soviet state), Shostakovich did not turn to the string quartet until 1935, around the time of the scandal over the opera Lady Macbeth of Mtsensk. Some commentators see this as a fault-line in his musical output. By resorting to string quartets, he was able to convey, however obliquely, his private ruminations. They reveal him as one of the greatest masters of the medium.

The Casals quartet won plaudits for its recording of the first five quartets and this collection (Nos. Six to Twelve) will, I’m sure, elicit similar praise. The sonorities intrigued me until I read that they used a combination of baroque bows and modern instruments. Mystery solved. The reviewers challenge with so much of this music...