OPERA / A catalogue of unspeakable acts: In Deborah Warner's staging, Don Giovanni's sexual conquests only just stop short of sacrilege. No wonder it upset a few of the Glyndebourne faithful. Edward Seckerson heard the catcalls

The rumoured condoms never materialised, the laws of indecent exposure were not flagrantly breached, but this Don Giovanni did - symbolically at least - finally add the Virgin Mary to his catalogue of conquests. It was bound to come: the ultimate woman, the ultimate conquest, the ultimate blasphemy. And, for the producer Deborah Warner, the ultimate collision between sex and theology, one last gesture of defiance for a man who shakes his fist at the Almighty and says, 'I will not repent.' Social and moral collapse. A glimpse of true hell on earth. It goes to the heart of what the Don Juan legend is all about, and it goes to the heart of Deborah Warner's new Glyndebourne production.

I'd like to think that the howls of derision that greeted her first-night curtain call were an expression of genuine shock and outrage - whatever the provocation. But I suspect it was the old story: a comfortable audience uncomfortable with any new angle on old material, a knee-jerk reaction to the modern dress and brutalist designs. But we've been there before so many times. Heavens above, she even gave us the fires (or was it the back-burners?) of Hell. Given the post-Aids context, can you imagine where we might have been headed? But Deborah Warner is too good for that. Her Don Giovanni is about the people, about resistance (or otherwise) to the force of immorality. That's a drama for any time, any place.

In that, of course, she has Mozart and Da Ponte on her side. They knew better than most who had tackled the Don Juan myth not to be too specific about the details. They knew that period and social context were actually irrelevant, indeed a distraction from the central issues - above all, the Don himself. A man, a monster for all seasons. The less we know about him, the better. He's the force of degeneration. The outsider, the solitary, the predator - classist, sexist, antisocial, antichrist. And he's irresistible. That's what's frightening. Warner has him constantly on the move. When he isn't on the prowl, he's on the run - from vengeance, human and divine. He is always changing shirts (a brilliant touch). And there's never time to button them. Why bother? Leporello, his sidekick, valet (conscience?), always has a freshly laundered one at the ready. It becomes almost his sole function.

So it's a jungle out there - a concrete jungle in Hildegard Bechtler's coldly deconstructivist setting. A no man's land, a space without identity, a gallery without exhibits: descending steel walkway, polythene sheeting, sulphurous light, and a moving, tilting central platform that seems to symbolise instability. The set is as heartless and unforgiving as Don Giovanni himself. It makes you feel dirty. It's oppressive.

But that's entirely in keeping with the show as a whole. Perhaps the most controversial aspect of Warner's production is its pace: languorous, heavy with the smell and lure of sex. The insinuations, the pregnant pauses, the slow- burning recitatives - they are all a part of it. It begins with Leporello's scene with the distraught Donna Elvira. The humour of the 'catalogue aria' should stick in your throat as Leporello, in the most sensuous music imaginable, goes on to give Elvira chapter and verse as to his master's predilections. With Sanford Sylvan's mellifluous singing and Simon Rattle's free rein on the music, its beauty was suddenly appalling. Elvira's distress - so real - made it all the more sadistic. Likewise, Don Giovanni's ravishing 'La ci darem la mano' with which he serenades Zerlina whilst fondling her wedding dress. She puts it on: he even arranges the veil for her. She is hypnotised. Sex acts like a drug in this production. The Don is both user and pusher. And violence is always only a step away. The sexiest aria in the piece, Zerlina's 'Batti, batti, o bel Masetto' (persuasively sung by Juliane Banse), is a plea for chastisement.

But there is a high price to pay for Warner's slow-burn approach. The reckless dash of the narrative - the elements of black farce. Mozart and Da Ponte performed the most miraculous juggling act with the comedy and tragedy. In her search for truth on the dark side (every recitative is played to the hilt - drama, not just information), Warner has denied us that heady brew of speed and cynicism. It's the Don's longest day in more ways than one. At least it feels that way. Rattle's conducting certainly doesn't lack pace. Period instruments or not, he never allows style to inhibit the expressive reach of the music. His marvellous Orchestra of the Age of Enlightenment is alive with intrigue and insight - playful, introspective, defiant. The opera's characters are fleshed out here, their emotional responses endorsed and finessed in a capricious and poetic alliance between instrumental and vocal lines.

And whatever one's feelings about the evening, Rattle and Warner have themselves a cast - not a collection of principals. I've mentioned Sanford Sylvan's beautifully sung Leporello. John Mark Ainsley's Don Ottavio should share the vocal honours with him. His 'Dalla sua pace' displayed a sensitivity way beyond the sound - which was, as ever, lovely. Hillevi Martinpelto's Donna Anna and Amanda Roocroft's Elvira were, vocally speaking, almost too well matched, but more than equal to the temperamental configurations of their impassioned music. In a rare but choice moment of visual comedy, Roocroft gave vent to the scorn of her first aria whilst fixing her hair. Gilles Cachemaille's Don was more wholehearted than charismatic, either vocally or dramatically. An ordinary bloke, your average oik. But somehow that made him all the more frightening.

An evening of contradictions and unfulfilled promises, then. I like Warner's plain-speaking, her lack of dramatic clutter. But she hasn't pulled this one off. The feeling is that she started something she couldn't finish. But the wicked spectacle of Don Giovanni hauling around his other dinner guest, a plaster cast of the Holy Mother (in a neat twist, the real 'stone guest', the Commendatore, is always very much flesh and blood), the mock feeding of the bread and wine, and that final unspeakable act - these are things that Glyndebourne audiences might take some time to forget.

'Don Giovanni' is in rep to 24 Aug at Glyndebourne Opera House, near Lewes, East Sussex (Booking: 0273 813813) and, in a semi-staged concert performance, at the Proms on 29 Aug (071-589 8212)

(Photograph omitted)