Maurizio Pollini,  Royal Festival Hall, London

Maurizio Pollini was, in his prime, arguably the greatest pianist in the world. In recent years there’s been a  falling-off from his once immaculate technical control, but at 81 he still fills large halls. And so he did at the Southbank, for an eagerly anticipated recital he’d postponed three months previously for reasons of ill health.

Opening with Schumann’s Arabesque, he brought out that work’s unassuming conversational charm, with its inner voices sweetly contending. Then, after applause, something un-programmed and sinister came: a short barrage of strident and dissonant chords, like a clumsy improvisation which broke off angrily. This keyboard outburst was loyally – if diffidently – applauded, after which Pollini retired to the wings for a long and unexplained pause.

When he reappeared, it was accompanied by a man bringing a music-rest and a sheaf of loose pages which Pollini scrutinised hesitantly, before launching into Schumann’s virtuosic Fantasie in C. He was clearly bothered by the score, which he seemed to be sight-reading, rather than playing with the assurance one would expect of a man who had performed this work all his life. As he shuffled and re-shuffled the pages, all the impetus of Schumann’s passionate music drained away, and at one point he gave up, surveying the now-disordered score with pathetic puzzlement. This was excruciating to watch. Were we watching the disintegration of a once supremely powerful musical mind?

Maurizio Pollini ©Mathias Bothor

Not entirely. Pollini suddenly pulled himself together and got his own voice back, though with memory lapses, and missing a couple of beats each time he had to turn a page. The final movement sounded the right, darkly ruminative note, and to everyone’s relief he coasted home with at least the remnants of his old authority. Memory for concert pianists is a mysterious thing. Focus too consciously on individual notes and you can come to grief: muscle-memory should carry you through.

Would Pollini be dissuaded from returning to play a second half which had to include one of Chopin’s most technically daunting pieces? A regretful managerial speech – ‘Mr Pollini is indisposed and will not continue his recital’ – would surely have been appropriate.

But no. The lights went down, and Pollini reappeared this time with a page-turner in tow, and the first piece of the second half – Chopin’s Mazurka in C minor Opus 56 No 3 – came over with its poetry exquisitely intact. The Barcarolle, which followed, was its normal expansive self, if somewhat splashy. But how would Pollini dare with the Scherzo in B minor? Well, he just scraped through it, but the result was anxious, scrambled, and technically at best approximate. Usually he’s generous with his encores, but for once – mercifully – there was none.

Cue the inevitable standing ovation – Pollini’s fans are blind to any defects – which he acknowledged with gestures more pleading than triumphant. For this man really is loved. What we were applauding – and thanking him for – was half a century of sublime music.

That now seems to be over. And I write not out of Schadenfreude but in sympathy, as a reminder of the dread precariousness of every concert pianist’s life. They must have enormous physical stamina, and must accomplish extraordinary feats of memory. And, like unprotected circus performers in the old days, they must daily risk everything, without any kind of safety net. In the face of such unforgiving pressures, they need to know when it’s time to stop.

Pollini has fallen from his high trapeze.  And in professional terms, a fall like that can be fatal.