Every so often a work appears that for sheer size breaks its mould: Beethoven’s Eroica, Mahler’s Third Symphony, Brian’s Gothic, Maw’s Odyssey. The chamber and instrumental genres have seen this, too: Schubert’s late Quintet, Schoenberg’s First Quartet, Sorabji’s Opus clavicembalisticum. These last are apt forebears for Alastair Hinton (curator of the Sorabji Archive). His String Quintet (1969-77) moves in timescale from the late Schubertian to the Sorabjiesque, while the Schoenberg of the D major Quartet and Verklärte Nacht provides the wellspring of the work’s harmonic language. (There is a good deal of Strauss present in the mix, but scant obvious Englishness.) Schoenberg’s Second Quartet, with its use of a female singer, also provided the initial model.

The Quintet’s huge duration derives from the fifth and last movement (with its large array of texts) which plays for more than two hours – longer than all the above works, the Sorabji aside – whereas the first four collectively last well under one. Indeed, the first three, taking up Disc 1, make a most effective quintet on their own. However, this is not a work that monstrously outgrew its plan: Hinton designed it this way from the outset. The Quintet is full of interesting sonorities, such as the monumentally spacious openings of the first and fifth movements, the manic ticking of the Shostakovich-like first scherzo or the wonderful ‘Aria’ for soprano and double-bass in the finale’s second quarter. Much of the work, though, is contemplative and searching, the first four movements functioning like an extended exposition with the finale an exponential development. Derivative and uneven it may be, but it is also truly individual.

The performance is astonishingly committed and persuasive, all the more remarkable coming from an essentially scratch ensemble. There are one or two passages where the playing sounds ad hoc, but it is in no sense deficient. The recording is beautifully done, spacious and natural; Sarah Leonard is a touch recessed, deliberately so, according to the composer’s long, semi-autobiographical note. Not a work to be encountered casually, but worth the effort and I hope Altarus’s enterprise in recording it is amply rewarded.