Fazil Say, Lucerne Piano Festival, Lucerne

The Lucerne Piano Festival attracts an influx of pianophiles every November to the town's state-of-the-art lakeside hall. It has just been welcoming some of the piano world's greatest artists including Murray Perahia, Maurizio Pollini and a host of young up-and-comers. Plus one dud.

Fazil Say is a megastar in his native Turkey and has been touted as something of a genius. Three possibilities could explain this dismal evening. Perhaps he was having an off-night; perhaps he's losing the plot under pressure; or perhaps he's just not a very good pianist.

Hunched at the keyboard with a desperately rounded back under two frightful shirts (someone should call Gok Wan), he appeared absorbed in his own world, without much inclination to draw in his listeners. Madness, not genius? Not even that: only a dislocated, self-centred, slapdash eccentricity that did the music few favours.

He propped the score on the music stand for every piece except the Mozart A major Sonata K331 and his own work. Fine – there's too much mystique about playing from memory – but I couldn't help wondering, given the wrong notes and the lack of structural awareness, whether he had actually looked at the Janacek Sonata 1. X. 1905 in advance. It's an empathetic, tragic work commemorating the death of a demonstrator at the hands of the police; but what we heard was hopelessly wayward at best, and at times incoherent.

Beethoven's last sonata, Op. 111, was a disaster, as splashy as if Say had jumped into Lake Lucerne. And earlier the intricate fingerwork of the Rondo alla Turca that closes Mozart's K331 sonata was lumpy and scrambled. Not only did he lack the musical and aesthetic judgement for these masterpieces, but his technique was inadequate to their demands. In such a prestigious series, this is fairly shocking. What was he doing there?

Yet Say offered his best in his own compositions, represented here by Inside Serail, a mash-up of the Mozart sonata through a raptly Sufi-esque prism. Now at last he seemed at one with the music, the audience and himself. His own transcription of the Bach organ Fantasia and Fugue in G minor BWV542 was also reasonably impressive and wins him a second star. Presenting his own music, perhaps in an experimental jazz club, he might offer something more worthwhile.