The agony and ecstasy of a Last Supper reunion

When J S Bach wrote the St Matthew Passion, belief in God was a given - like breathing, like death. Even for the modern, largely agnostic audience, faith is what transports that work; you may not share the belief, but you can admire the belief that brought it into being. But among today's post-Darwinian, post-Holocaust, post-Hiroshima composers, such innocent devotion is rare. Even their patrons have changed; the commission for Harrison Birtwistle's "dramatic tableaux", The Last Supper, came from the Royal Festival Hall, the Deutsche Staatsoper and Glyndebourne - cathedrals to Art, not God.

When J S Bach wrote the St Matthew Passion, belief in God was a given - like breathing, like death. Even for the modern, largely agnostic audience, faith is what transports that work; you may not share the belief, but you can admire the belief that brought it into being. But among today's post-Darwinian, post-Holocaust, post-Hiroshima composers, such innocent devotion is rare. Even their patrons have changed; the commission for Harrison Birtwistle's "dramatic tableaux", The Last Supper, came from the Royal Festival Hall, the Deutsche Staatsoper and Glyndebourne - cathedrals to Art, not God.

The subject of The Last Supper - a supper that reconvenes the original diners to chew over the fat of the 1,977 years since the last Last Supper - seems tailor-made for Birtwistle, a modernist whose music regularly elicits the word "timeless". You may cringe when Simon Peter sings the words "I think we've been invited back into Space/Time, until we find mortality again" (more of Robin Blaser's libretto later), but you can't fault Birtwistle's adept referencing of all things musical and religious from Pérotin to Ligeti in order to illustrate the floating space/time capsule that is the disciples' dining-room. Sadly, Birtwistle's score is the only aspect of The Last Supper that makes any cogent argument.

The 12 disciples are ordinary blokes. Most of them look as though they're off to a PTA meeting, though sharp-suited Matthew (the tax-collector) is still a yuppie in Y2K and Judas appears to have bought up most of Joseph (the designer not the saint) with his 20 pieces of silver. But these "ordinary" men weep, lay hands, clap, dance and hug and by the time Christ arrives in his cult-guru uniform of a white linen suit, you half expect him to tell them how to celebrate their masculinity. The upshot of this is that the passion of the disciples is shown as fanaticism, the teachings of Christ as pop-psychology.

Was this the intention? I doubt it. Blaser's libretto makes some intelligent points about the interdependency of doubt and belief but is so giddily ecumenical that it lapses into the kind of cuddly cod-philosophy spouted by the good aliens in sci-fi films. Maybe they should have called it Return of The Last Supper? "They" - us, the audience, the human race - "want us to look with them through the three zeros of the year 2000" sings the excitable Andrew (Colin Judson). Hmmn. We learn that Blaser's movie-star Christ was personally upset by the Holocaust and that he feels aggrieved by history's treatment of "Jews, Blacks, aborigines, women, Gypsies, homosexuals, and their songs" but as he tells us this and washes the feet of his disciples, he also washes his hands.

The performances of cast, chorus and orchestra were all of a high standard. Hilton Marlton (a brilliantly agitated Simon) and Andrew Watts (a fervent James with an extra-fruit zing to his jammy counter-tenor voice) stood out, with excellent acting and singing. Handsome, blond William Dazeley sang Christ with a cool gleam and was matched by handsome, black Thomas Randle as Judas - an impassioned, brave and believable performance. Alison Chitty's lucid designs helped to focus the rambling drama, deftly contrasting the airport-lounge rootlessness of the dining room with a series of Catholic-kitsch tableaux vivants that Vatican City trinket-sellers would kill to see.

Birtwistle's urgent score thrusts out chunks of beauty; colours from the souk to the symphony hall and textures from the antiphonal rigidity of the Lutheran mass to the lush harmonic swamp of Schoenberg. The disciples' ensembles are densely harmonised like an intoxicated Glee Club and the part of Ghost (radiantly sung by Susan Bickley) is the kind of tour-de-force role that mezzos will fight over. But the underlining of each phrase quickly wears. You wonder where the emotional arc of the piece lies when every word seems to have equal weight, and the a capella choruses that pause to explore a specific mood are the most successful sections.

If asked for a one-line verdict of The Last Supper, I'd say it is a glorious failure. The libretto acknowledges Hannah Arendt, Thomas Traherne, A M Klein and Richard Crashaw, yet assumes a woozily anti-intellectual shrug in response to the last two millennia. The problem with spiritual tourism is that it lacks focus - and to a certain extent the same charge can be levelled at the music. But it's certainly worth seeing; music this commanding and ideas this annoying are a tonic to core-repertoire saturation.

Leonard Slatkin's inaugural concert with the BBC Symphony Orchestra was a double celebration with the orchestra's 70th birthday. Appropriately enough, they chose Barber's violin concerto to reflect Slatkin's nationality, Prokofiev's concert version of Alexander Nevsky to reflect his family's Russian roots, and two new commissions by Mark-Anthony Turnage and Simon Bainbridge to reflect the BBC's commitment to British music. Bainbridge offered slithering rattlesnake modernism to offset the romanticism of Barber's concerto - played with absolute control by Joshua Bell. Turnage plucked a street-wise trombone melody from the borders of ska and played around with the symphonic soundscape until the Barbican shook. Alexander Nevsky was polished and honed (in so far as a crude juxtaposition of samovar sentiment and genocidal massacres can be) but the highlight was the orchestra's assured support of Bell in the Barber - a clear hint that Slatkin can ensure a new, higher standard from this orchestra.

I dodged the first night of The Last Supper in order to make my own pilgrimage; Kathleen Battle was in town with Kent Nagano and the London Philharmonic Orchestra in a bizarre programme that jumped around Mozart's Figaro, Thomas Adÿs and Exsultate Jubilate before heading into the phallic thrust of Strauss's Also Sprach Zarathustra. At 52 Battle still looks incredible, but her voice (always of the small but perfectly formed variety) is now so miniature that it's in danger of disappearing. In the auditorium we could hear her warming up. High As and Bs rang out, shivering in tones of gold and silver, but on stage she gave a merely twinkly performance. It was all very pretty, but she certainly wasn't how I remembered her. What was she saving herself for? Well, it wasn't the pearly top C at the end of her immaculate but scarcely audible Exsultate Jubilate. It was her encore.

After much effusive bowing, Battle took a note from the leader's violin and stood alone to sing an unaccompanied Spiritual. "Over my head, I hear music, I hear music in the air" she sang, her voice sliding up to the sky then swooping low like the tenderest words of love you could possibly want to hear. "I hear music in the air," crooned Battle, pulling the consonants from deep in her body and casting that rich, glorious sound across the Festival Hall. It was pure magic. "There must be a God somewhere!" she sang, glowing and shining on the stage. I'm not sure about the morality of coyly teasing an audience only to deliver this astounding encore, but at that moment how could I disagree.

'The Last Supper': Glyndebourne Touring Opera, various venues to 7 December (01273 813813 for info)