A year or so ago I chanced upon a CD on the French Assai label featuring Josef Rheinberger’s two-piano version of the Goldbergs as arranged by Reger, a scrumptious, harmonically enriched embellishment on Bach’s original design, drunk on counterpoint and profoundly pleasing to the ear. Concerning his discursive but consistently engrossing Gilded Goldbergs (1992-97), Robin Holloway confesses that if at the time of starting them he’d realised that Rheinberger had published the entire work he’d ‘surely not even have begun’. Which would have been a crying shame, for this is a marvellous work.

But where should I begin? Most usefully perhaps with Holloway’s initial prompt, where, ‘frustrated as a single pianist by inability to clarify the close-weave canons or manage the more fiendish hand-crossing numbers so idiomatic on a two-manual harpsichord’ he prepared his first transcriptions. So far, so pleasurable – but then inevitably the full artistic implication of what he was doing struck home. It was only later, after much agonised self-questioning, that he decided to ‘go for the gilding and lose the guilt!’ Holloway himself provides an exhaustive history of these Gilded Goldbergs’ composition, taking a variation at a time in no particular order, then working towards a schematic design and overall balance: eventually two substantial parts subdivided into five ‘sets’.

Bach’s original is thrown in at the deep centre of a swelling harmonic sea, sometimes as a moment of ineffable calm (Variation 18, a ‘canon in sixths’), at other times more like an oncoming tidal wave (Variation 29, ‘Toccata with clusters’). The use of modulation is often alarming but always musically effective and never more so than in an ingenious re-working of the closing ‘Quodlibet’ (Variation 30), which traverses ‘all 12 keys’, ending in D. The most substantial movement is a nine-minute take on variation 13, ‘a double variation juxtaposing…the airy florid tranquillity of piano one in G with the dark, clenched Dowland-lute-song secretiveness of piano two in E flat minor’. Significantly named Cantilena 1, it functions in parallel as the expressive heart of the work with Cantilena 2, the so-called Black Pearl of Variation 25, initially ‘scrambled’ then re-structured but with no pitch transpositions.

And there’s the humour: references and cross-references, hilariously in Variation 19, and a ‘brief history of Austro-German music in triple time’, where Bach forms a musical chain with Haydn, Mozart, Beethoven, Schubert, Schumann, Wagner, Richard Strauss, Mahler, Mendelssohn, Bruckner and probably more (a game in itself, identifying them all).

Holloway’s ear for nuance, not to mention the sheer ingenuity of his invention, left me open-mouthed with admiration and it’s surely a tribute to the Micallef-Inanga piano duo that I only thought of mentioning them towards the end of the piece. For the rest of the time it was the music and only the music – Bach’s and Holloway’s, but ultimately more Holloway’s – that seemed to matter. And that surely is praise beyond measure. Fine sound, too, the icing on a very nutritious cake (retailed, by the way, as two CDs for the price of one). Whatever your CD priorities to date, this one surely has to fly straight to the top of your wants list, but I’d also suggest Hyperion re-engage Micallef-Inanga for Rheinberger-Reger. That, too, would be a more than worthwhile venture.