CLASSICAL Philippe Cassard's Debussy Day Wigmore Hall, London

Sunday at the Wigmore Hall saw pianist Philippe Cassard launch a captivated audience on "a marvellous non-stop journey to the heart of a wondrous universe". That "universe" (as Cassard himself called it) embraced the entire range of Debussy's solo piano music, from the sweetly aromatic "early" Arabesques to 12 challenging Etudes composed during the First World War. Each of the four programmes - they started at 11.30am, 2.30pm, 5pm and 7.30pm respectively - featured at least one work by another composer that served as a sort of thematic linchpin.

The first lap was a packed "Coffee Concert" on the theme of dedications and influences: the Images, Book One (with its noble "Hommage a Rameau"), the Suite bergamasque, Hommage a Haydn, Reverie and Le petit negre with its unmistakable echoes of Chabrier. Rameau made an appearance with a familiar Gavotte variee, then - even before the applause had died down - Cassard bounded in with Pour le Piano's energetic Prelude.

The decision to eschew chronology in favour of "themes" guaranteed maximum contrasts in tone, style and mood. For example, the second recital centred around the idea of harmonic exploration: the pre-Bartokian Etudes provided the pivot and there was a witty connection between the last piece in the Children's Corner Suite - the "Golliwog's Cake-walk" with its Tristan parody - and the transcription of Wagner's "Traume" that followed. There was an unexpected "encore", too, in Erroll Garner's smoky Moment's Delight, a piece that was apparently much influenced by Debussy and that, as the pianist himself smilingly confessed, was "rather less difficult than the Etude I've just played".

Viewed overall, Cassard tended towards quick tempos and outward drama in the faster pieces, dropping or smudging the odd note but invariably capturing the music's spirit. His mastery of Debussy's sophisticated harmonic world was tellingly exemplified in the haunting "Pour les sonorites opposees" from the Second Book of Etudes, while the third recital was crowned by an inspired reading of the first book of Preludes. Best of all was "La cathedrale engloutie" where, after the majestic central climax, Cassard conjured up watery depths with a veiled, shimmering tone.

Faure's Sixth Nocturne marked the transition between Debussy's own Nocturne of 1892 and the first book of Preludes, whereas Chopin provided the principal point of reference for the evening concert. Cassard opened with the achingly sad La plus que lente, progressed through a trio of early pieces, followed by three from 1904 (including a luminous, technically dazzling L'Isle joyeuse) and ended with two "Book Twos" - of Preludes and Images.

Throughout the course of the four recitals, Philippe Cassard exhibited impressive powers of concentration, and his physical stamina was remarkable. It was a measure of his achievement that, for the much of the time, our attentions were directed not to the pianist but to the music he was playing. Here was proof beyond doubt that Debussy's piano music can overwhelm the listener with (and here I quote Cassard's own eloquent notes) "diverse feelings and sensations that combine admiration, pure sensual pleasure, curiosity, a dreamy abandon, amusement and melancholy". Robert Cowan