Krystian Zimerman, Royal Festival Hall, London

It’s fitting that the South Bank should mark Chopin’s alternative birthdays - scholars can’t agree on the correct one - with performances by two great Chopinists.

Next week we will hear Maurizio Pollini, these days an uneven performer, but whose recordings are beyond compare. This week we heard that reclusive Polish monstre sacré Krystian Zimerman, whose fastidious integrity has all but impelled him to quit the recording game, and who last year interrupted one of his American recitals with a furious denunciation of that country’s foreign policy.

Now 56, but with the mane and demeanour of a grand old man, he swept on to launch into a rendition of Chopin’s exquisite Nocturne in F sharp minor: we might have been listening to his hero Artur Rubinstein, so artlessly expressive was his sound. Then we were plunged into the baleful world of Chopin’s second sonata, with the initial war between the hands brought out in high relief. The second movement had the heavy morbidity required to segue into the bleakness of the funeral march, but this - despite Zimerman’s visible determination to wring a huge sound out of his instrument - was strangely lacking in heft. Only in the lyrical middle section did the movement take wing: its mournful sweetness led back to a march which magically faded away. But the ‘wind over the graves’ finale was turned - as it is by many pianists - into a stunt: to play this so fast that the individual notes blur into a wash of sound is to short-change the audience of its poetry.

The rest of the recital was surprisingly underwhelming, given how superb Zimerman’s early Chopin recordings are. The Scherzo No 2 felt rushed and smudged, and the same defect marred the first movement of the Sonata No 3 which followed: only in its third movement did Zimerman’s old artistry emerge, as the notes sang out with serene eloquence. Then, with the Presto, it was back to rushing and smudging. Closing with an over-brisk account of the Barcarolle - one of Chopin’s most prophetic works, with ever more daring harmonies clothing its graceful, rocking rhythm - Zimerman yet again failed to honour the poetry and majesty of Chopin’s music. Half the hall obediently rose in a standing ovation - he’d had a massive publicity build-up - but the rest of us were left wondering what had happened to his once-shining talent.