The number of pianists who have recorded memorable accounts of the Diabelli Variations is surprisingly small. Among long-established classic versions, the names of Schnabel, Rosen, Kovacevich and Brendel immediately come to mind – and, of course, Rudolf Serkin: distinguished mentor of Ronald Brautigam, who emerges here as the second pianist to record a plausible account of the Diabelli using an instrument of the period.

How the waltz theme itself is played is often a useful pointer to what follows. Brautigam’s articulation, like Serkin’s, calls to mind Donald Tovey’s description of Diabelli’s theme as ‘healthy, unaffected, dry, energetic’. That’s a fair characterisation of the work itself, which is why the best performances of this encyclopaedic distillation of Beethoven’s genius as a composer for the piano deliver the music with the directness of an engraver pressing his image to the page.

Brautigam’s instrument is a copy of an 1822 Graf by the distinguished piano maker Paul McNulty. All we know of the instrument on which Andreas Staier made his in many ways admirable 2010 Harmonia Mundi recording is that it is ‘a fortepiano after Conrad Graf’. Staier clearly relishes the Graf’s sonic potential: witness the bassoon-stop drone he deploys in the cod-Mozart Variation 22 or the ‘janissary’ stop (a wire coil struck by a pedal-operated hammer) which he uses to bizarre effect in the toccata-like Var 23.

Brautigam deploys no such devices. Take the profoundly mysterious Var 20. Where Staier uses the fortepiano’s pedal shifts and felt-covered moderator stop to conjure up velvet-soft sonorities, Brautigam (playing a little too loudly perhaps) is interested only in the musical essence – in this instance, the perfectly articulated sounding of those weird chordal progressions which dot the landscape like the stones of some ancient henge. That mindset, and Brautigam’s superior technique in the fierier variations, is the difference between the two performances. Aficionados of old pianos may prefer Staier’s approach but lovers of the Diabelli itself are more likely to find fresh interest in Brautigam’s period take on a classic reading.

Brautigam’s fill-up reworks for solo piano the Six National Airs With Variations for piano with flute or violin which Beethoven wrote for publisher George Thomson in 1818. Thomson was aghast at their difficulty but on this occasion Thomson’s despair can be our delight.