The programme for Hélène Grimaud's Festival Hall recital was identical to that of her most recent CD: the Second Sonatas, both in B Flat Minor, by Chopin and Rachmaninov, together with Chopin's Berceuse and his Barcarolle in F Sharp. The disc is timed at 62 minutes, and the concert could be construed as an object lesson in how to make around an hour's music stretch to an hour and three quarters in performance. She started a few minutes late, left the platform more than she needed to, and kept us waitingafter the interval. There was, needless to say, a signing session after the recital.

All this opens her to charges of promotionalism. That they don't quite hold is largely due to the sincerity of her playing. Mystically inclined in her thinking, Grimaud can be both visionary and inspirational. Even so, she got off to a slowish start. She has only recently returned to Chopin after 15 years of not performing his music, and occasionally it showed. The F Sharp Barcarolle sounded muddy, though she turned the Berceuse - with its insistent figurations - into something altogether more ominous than a lullaby.

During the Chopin Sonata, she had to do battle with fits of coughing, protracted nose-blowing and, at one point, a flashbulb going off somewhere in the audience. Her performance, understandably, failed to cohere until she got to the famous funeral march. Its central section, startlingly, seemed to rise out of numbed grief rather than swerve into nostalgic lyricism.

The audience managed to shut up for the Rachmaninov - a performance of furious emotional range and depth. Subordinating any self-conscious virtuosity to expression, she seemed to live out the music rather than simply play it. This was Grimaud at her considerable best.