Classical: Debussy: Painter of Dreams Barbican Hall, London / Radio 3

Thanks to the embrace of the BBC's Sounding the Century series, Michael Tilson Thomas and the LSO's three-concert "domestic" Debussy festival at the Barbican, Painter of Dreams, has been shimmering across the airwaves - the first and last concerts were relayed live on Radio 3, the second will be broadcast next Monday - surely establishing something of a record for the number of people listening to this composer at any one time.

The two concerts I attended - the second (on Sun 23 Feb) and the third (last Thursday) - were both packed, suggesting that interest in Debussy, that oh-so-private composer, is surprisingly large. One-composer festivals are currently all the rage - Schubert, Brahms, Stravinsky - and now Debussy. Historical context may be lacking but, as with the LSO's splendid offering, some wilder shores can be explored.

Both these concerts included real rarities - interestingly enough, all of them under the guise of "incidental" music. Debussy's Le Martyre de Saint Sebastien, on the Sunday, was given an exceptionally rare outing. This music for soloists, chorus and orchestra was originally written to accompany a lavish mystere by Gabriele d'Annunzio, a five-act extravaganza lasting five hours and involving the dancer Ida Rubinstein, the choreographer Michel Fokine, and the painter Leon Bakst. Its premiere, in Paris in May 1911, was not a success and a reduced version, with linking narration, was devised for concert use. The LSO's performance revealed a bleeding hulk with some of Debussy's most ravishingly beautiful music. What with spears and wounds, the aura of Parsifal hung heavily over proceedings, but the obvious homoerotic angle on the story seemed strangely muddied by the use of a woman narrator, for it's "she" that plays Sebastian, who's mistaken for Adonis and loved by Caesar. Leslie Caron, in rather over- dramatic form (nastily amplified), boomed her way through. Paula Almerares coped with some stratospherically high vocal writing as the Virgin Erigone, Vox Sola and Soul of Sebastian, even if her vibrato was wide. Jacqueline Miura and Anne Larsson sang Mark and Marcellian, the (unlikely) twins, and the vast LSO Chorus was in magnificent form.

The evening had begun with an effervescent and apparently effortless performance of what is arguably Debussy's greatest orchestral score, Jeux. On Thursday, the main "find" was La boite a joujoux, the composer's enchanting score for a children's pantomime. Following on stylistically from Jeux (and written two years later), it seems odd that this music is so rarely heard; a perfect children's ballet awaits an enterprising choreographer. But the score, like Jeux, is treacherous, certainly not for any faint- hearted conductor or orchestra. Tilson Thomas coaxed aural charm from the LSO, the pianist John Alley making light of a demanding part. Lucy Wakeford displayed a fine range of colours and a very musical mind as the chromatic harp soloist in Danse sacree et danse profane, and was young enough to giggle when offered the regulation bouquet. The concert began with fragments from an aborted 1904 project on King Lear (Le sommeil de Lear, tender and sensuous, was particularly appealing), while an Images of astonishing clarity and nuance merely confirmed that MTT and the LSO make extraordinary Debussy protagonists.