For Vincent d’Indy, the near-forgotten Dessau court composer Friedrich Wilhelm Rust (1739 96) was ‘the connecting link between Haydn and Mozart on the one hand, and Beethoven on the other’: a flattering verdict, and, on this showing, not one I can relate to. Listening to these sonatas and variations composed between the mid-1760s and the mid-1790s, I’d place Rust’s music somewhere between Carl Philipp Emanuel Bach – one of his teachers – and Haydn, without the genius of either. The early G minor Sonata, in particular, sounds like a series of improvisatory fantasies, à la CPE, though you need Bach’s harmonic imagination and sense of dramatic timing to consistently hold the attention. Bachian Empfindsamkeit (‘heightened sensitivity’) also colours the two later sonatas, where feints at Classical equilibrium are undermined by cadenzas, toccata-like flurries and a general air of waywardness.

Jermaine Sprosse, who has championed and edited Rust’s keyboard music (he adds his own slow introduction, obliquely quoting Haydn’s London Symphony, to the D major Sonata), seeks to enhance this waywardness at every turn. He clearly has a brilliant technique, as evidenced by the dashing and, to my ears, Scarlatti-influenced finale of the C major Sonata. His imagination, too, is never in doubt. Playing on a resonant modern copy of a double-strung clavichord and a finely restored Stein fortepiano, he distends and dreams on the music at the slightest provocation. This can work up to a point, though it becomes near-intolerable in the Allegros of the C and D major sonatas, with their enervating rallentandos and surreally protracted pauses. With a nod, perhaps, to d’Indy, Sprosse evidently sees Rust as an out-and-out proto-Romantic. But I’m unconvinced by his attempts to distil soulfulness from invention that is often no more than agreeably routine. The Variations, on a homely canzonetta by Rust’s contemporary Johann Schulz, likewise suffer from an excess of ‘sensibility’, with barely four bars played at a steady tempo. Towards the end of my listening I jotted, impatiently, ‘If only he’d let the music “spin”.’ Which rather sums it up.