Steven Osborne, Wigmore Hall, London

Steven Osborne tells nothing but the truth. As a pianist, he hasn't an ounce of excess fat. His encore on Saturday was Schumann's song "Widmung", without the voice, of course, but with the melody, which sang, as fresh and unspoilt as the moment it was born. It was smart and unexpected of Osborne not to play Liszt's transcription of the song, and balm indeed after Liszt's overextended "Bénédiction de Dieu dans la solitude", though that, too, was played with warmth rather than grandiloquence.

Osborne is a slight figure and a delicate - though never a slight - player, yet the thunderous double octaves building up to the climax of Liszt's "Funérailles" were quite powerful enough. Perhaps in the second movement of Beethoven's Opus 90 Sonata, his quality of considerate affection bordered on the careful, and the piece felt just a bit long; but the lively switches of mood in the first movement were well caught.

The last book of Alkan's unusually concise Esquisses found Osborne equally alert to their dry, detached humour - light and brilliant in the opening Scherzettino, sweetly innocent in the second and sixth, crisp in the quick staccato chords of the eighth, and not overdoing the grotesque crunches of the ninth.

It was a pleasure, after that, to indulge in the darkly sumptuous romanticism of Medtner's Deux Contes, Op 20, the second of which is a powerfully driven, rather threatening piece. What a surprising and interesting programme it was, and what an incurious lot London concertgoers must be, for there were far too many empty seats.

On Tuesday, Osborne was joined by two pianists, one in each half of the recital. He and Paul Lewis have already played as a duet on one keyboard this season, and once again, I found their treatment of Schubert's great F minor Fantasy well thought out and beautifully polished; but why did the opening Allegro molto moderato have to be so mild and easy-going? True, Murray Perahia and Radu Lupu played it like this on a famous recording years ago.

Osborne and Lewis then changed upper and lower parts in Debussy's sensuous Six Epigraphes Antiques, producing the most magical pianissimi and pastel colours even though, on a horribly humid evening, their fingers must have been sticking to the keys.

Then, in Messiaen's Visions de l'Amen, for two pianos, Osborne was joined by a considerably beefier pianist, the redoubtable Martin Roscoe, who has made quite a thing of this work with Peter Donohoe.

Since Osborne took the first piano, with music in the higher register (save for his massive bass clusters in the sixth piece), there was no noticeable disparity in weight, and one player seemed to complement the other; they were so well co-ordinated, they might have been playing together for years. The audience rose to the occasion, thrilled.