On Tuesday night the 14-year-old Greek piano professor Dimitris Sgouros, with 35 piano concertos at his fingertips, gave his United Kingdom recital debut and half an hour's worth of encores to a packed Festival Hall.

His choice of Liszt's "Mephisto Waltz" was significant. Sgouros as pianist, just like Liszt as composer, is a deceptive virtuoso: the light of his technical mastery is blinding, his inventive energy self-regenerating to the point, almost, of self-intoxication. Yet that is not all. There is, driving the nerve and the muscle, a daemon that dares, a Faustian voraciousness for not only accomplishment but discovery, that bears up and substantiates his virtuosity.

For the moment though, the dominance of this spirit, a rare and rather startling quality in itself, means that one tends to learn rather more about Sgouros than about the composer in hand. Except, that is, when the two suddenly fuse, and then the sparks fly. This happened in the Liszt, and it happened most remarkably in the Brahms Paganini Variations, the most gripping performance I have ever heard.

It is inevitable, perhaps, that where style and technique have to bear the heavy burden of unripe emotional maturity, there will also be discomfort and distortion. The Chopin was disquieting in the first and fourth Ballades talent walked on a tightrope; and what we heard was idiosyncrasy and the heady excitement of discovery tottering on shaky foundation of understanding.

Hilary Finch