I am going to go out on a limb here and say that this is the finest album of contemporary chamber music I have encountered this year. I will go further, and suggest that Brian Elias’s String Quartet (2012) is a gem that should be in the repertoire of every British quartet. (Heath, Tippett, Villiers: take notice!) The Quartet is a tour de force of compositional ingenuity, its opening movement a concise, cleverly constructed set of double variations on a chromatic theme (using all 12 notes of the scale) and a second subject initially intoned by the viola. Elements of these are then worked through in the remaining three movements; the third span is a compellingly spectral scherzo. The Castalian Quartet play it for all its worth in a performance that is little short of a revelation.

Natalie Clein becomes the focus for the next 20 or so minutes in two remarkable solo cello works. The first is L’Innominata (‘The Nameless’, 2017), in which she is partnered sensitively by Danny Driver, a meditation upon the divine, the opening motif of which, as Peter Quantrill points out in his informative booklet note, seems like ‘a call to prayer – or the listener’s attention’ from which the rest of this fascinating 10-minute duo (with a very lively middle section) follows. The much earlier, unaccompanied Of Elutropia (1982) has an entirely different atmosphere and origin, a virtuosic fantasia inspired by the almost magical properties of the heliotrope (the gemstone also known as Indian bloodstone, not the purple-flowered plant) as described by the late 16th-century natural historian John Maplet.

Clein’s performances are the album’s high points (the magic is particularly strong in Of Elutropia), which the very early Duo for violin and piano (1970) and Three Scherzi (2004 07) do not quite match, finely though Thomas Kemp and Sophia Rahman render them. Rhythm is the dominant element in both works, almost choreographically so in the Duo, and it is fascinating to hear fleeting resonances of Shostakovich and Beethoven (among others) in the Scherzi. The concluding viola solo, But when I sleep (1987), follows suit. Inspired by a line in Shakespeare’s 43rd Sonnet (‘But when I sleep, in dreams they look on thee …’), it is beautifully played by Ann Beilby.

A companion album, ‘Music for Winds’ (SIGCD796), of scarcely lesser quality, has been released simultaneously, marvellously well played – not least the 2016 Oboe Quintet by Nicholas Daniel and the Sacconi Quartet – and also recommendable.