It has been a long, long time since Krystian Zimerman’s last solo recording. Think back to his Gramophone Award-winning Debussy Préludes in 1994. Yes, that long. So he’s up there with Sokolov in terms of rarity value. It is, he reveals in the booklet interview, all to do with approaching 60 (which he celebrated in December 2016, 11 months after this disc was recorded) and feeling that ‘it was time to find the courage’ for such works as the late Schuberts and late Beethovens, works that he has been playing for years. (By chance I heard him play these two sonatas live in the Royal Festival Hall last spring, when he stepped in at a moment’s notice after Mitsuko Uchida had had to withdraw. That’s what I call luxury casting.)

Courage? If only certain other artists could be so forbearing. You’ll notice there are no comparisons listed. That’s because this is one of those rare instances where they are not needed, do not illuminate the argument. Zimerman, quite simply, sounds like no one else. That’s partly down to the instrument, having inserted into his Steinway a keyboard he has made himself. Yes, you did read that correctly: for if there’s one thing that Zimerman is, it’s obsessive about the detail. So this keyboard is intended to be better able to sustain a cantabile line (this is done by having the hammer strike a different part of the string, if you want to get technical); it also has a wondrous clarity in the bass and is intentionally lighter-actioned, to avoid what the pianist describes as ‘the many repeated notes in Schubert … turning into Prokofiev’. Add to that the recording, made in the Performing Arts Centre in Kashiwazaki, a hall rebuilt after the earthquake of 2007, and you have the ideal circumstances for some very courageous Schubert.

Every element of these two sonatas has been thought out, considered; in the hands of a lesser artist the results could have been pernickety but instead they tend towards the transcendent. Take the second movement of the A major Sonata, D959. Just listen to the accompaniment, the way that the minutest of shifts in terms of touch recolours it. And then there are the gradations of colour, of dynamic. Nothing is ever fixed, but living, breathing. The movement’s extraordinary ‘nervous breakdown’ (as Uchida calls it) begins almost beguilingly, beautifully. He is much more controlled than some in the cataclysmic chords – passionate, yes, but less overtly desperate; some may not agree with this, but within the context of his reading of the movement, it works. As Zimerman leads back to the opening material, the sense of the initial music being scarred by what has happened is searing.

Time and again, Zimerman flouts received wisdom – his opening movement to D960 (of course with the repeat) sets off at a flowing pace but there’s plenty of time for the unexpected. Again, some might want a more simply flowing account but Zimerman holds you in thrall, suspends reality just as surely as Richter did (though in utterly different ways). He does the same thing in the slow movement: the first 30 seconds draw you into a world of such detail it’s as if you’ve never heard the piece before. And yet – and this is the miraculous bit – there’s no sense of that detail winning over long-term thinking (which can happen in Zimerman’s concerto performances). The instrument comes into its own where the music builds to climaxes without ever losing clarity in the bass.

The Scherzo of D960 is fascinating – it’s elfin, yes, but rather than mere playfulness there’s a gentleness to it. And rather than emphasising the contrasts of the Trio, Zimerman instead draws parallels between it and the Scherzo. The perfection with which he weights the closing chords is another heart-stopping moment. In the finale, there’s again so much that is inimitable: the opening octave is brusque in attack and yet not snatched, while the rhapsody of the playing is staggeringly beguiling, as is the interplay between silence and sound. It is a journey of great intensity.

Enough words from me: the playing speaks for itself. This is a marvellously life‑enhancing release. Go and hear it for yourself.