Music: Debussy’s wish comes true at the Barbican

Now Valery Gergiev has left the London Symphony Orchestra (not without sighs of relief from the players: his genius was unreliable), Simon Rattle is doing more than wait in the wings as his heir apparent. He doesn’t officially take charge until 2017, but between acts he’s much in evidence at the Barbican.

And he was there with the LSO last week for what was unequivocally the event of the New Year: Debussy’s opera Pelléas et Mélisande, staged by Peter Sellars and with a dazzling cast – if “dazzle” is the right word for this piece.

Debussy’s score is more a thing of quiet subtlety, with textures that don’t shine as much as shimmer. A successful reading loves them into life. Rattle didn’t stint the love, coaxing an exquisite beauty from the orchestra. Something that is, in truth, the focus of the writing.

With the instruments exposed, rather than buried in a pit, the focus on the exquisite really registered. Debussy once said that he imagined his orchestra as the forest in which the action takes place, wanting Mélisande to die among the first violins. Here at the Barbican he got his wish, because that’s just what happened – the LSO arranged it by leaving spaces among the orchestra for acting areas marked out by coloured strip lights glowing in a darkened auditorium. There were no sets or costumes – everyone wore black – but plenty of action. The staging flowed in abstract terms, with no sense of the separate scenes that parcel up the narrative, but it wasn’t hard to follow because Pelléas’s sung text gives you all the information you need about what’s happening and where.

What happens is a love triangle between two half-brothers, the childlike Pelléas and the macho Golaud, and the mysterious, elusive Mélisande who drifts into their lives like gossamer. Shrouded in medievalism, it’s a story that ends badly but with beauty in the telling. There were moments when Sellars approached hard-hitting social issues (here female subjugation in male-run societies), puncturing the tissue-softness.

Magdalena Kožená was too voluptuous as Mélisande, and vocally Pelléas (Christian Gerhaher, importing a dark tone to a lighter role) and Golaud (Gerald Finley, light-toned in a dark one) were too similar for comfort. But with artists of this calibre, what’s to complain about? Except that Golaud all but stole the show with singing of such tortured tenderness it had me weeping at the end. To make a semi-villain quite so sympathetic was a serious if unsettling achievement.