Arabella, Royal Opera House, London

Opera plots turn on some pretty fanciful actions, but none is more fanciful than the sight of Arabella delivering a glass of water to the man of her dreams over music suggestive, at the very least, of a vintage champagne. It's a symbolic gesture, of course - a commitment of betrothal simply made, solemnly sworn - but like everything else in this preposterous "lyric comedy", it's thickly spread by Richard Strauss and his librettist, Hugo von Hofmannsthal. They didn't agree over the glass of water, incidentally, but that's another story - perhaps even another opera.

Opera plots turn on some pretty fanciful actions, but none is more fanciful than the sight of Arabella delivering a glass of water to the man of her dreams over music suggestive, at the very least, of a vintage champagne. It's a symbolic gesture, of course - a commitment of betrothal simply made, solemnly sworn - but like everything else in this preposterous "lyric comedy", it's thickly spread by Richard Strauss and his librettist, Hugo von Hofmannsthal. They didn't agree over the glass of water, incidentally, but that's another story - perhaps even another opera.

The scene is a smart hotel in Vienna, the date very specifically set at 1860. So you can imagine the consternation felt by die-hard traditionalists when the curtain rose to reveal a super-chic, hi-tech lobby with a network of glass-encased escalators. My own first impression was that the designer, Erich Wonder, had been well named. But let us at least acknowledge that the traditionalists have a point. No one is suggesting that the set or Peter Mussbach's production are in any way "realistic" - the bellboys do Michael Jackson "moonwalks", for heaven's sake - but von Hofmannsthal has locked his text into the manners of a period when a family like Arabella's really could sink or swim financially on the basis of how well their daughters married. Then again, there is the question of Arabella's sister Zdenka. "We can't afford to bring up two daughters in this city," says mother (the excellent Cornelia Kallisch) - which is why Zdenka is brought up as a boy. At this point, "naturalism" goes straight out of the window.

So you pays your money and you takes your choice, though to judge by the loud grumblings in the interval, if your budget - and consequently your choice - doesn't stretch to the best central seats in the house, then this co-production with the Théâtre du Châtelet in Paris offers appalling sight-lines. Did no one check? Or was it too late to do much about it?

Sight-lines and moonwalks apart, I remain ambivalent about the production and the piece. Its pompous moralising and philosophising leave me cold. Its resolution is pure Mills & Boon, no matter how gorgeously Strauss dresses it up. I wasn't moved by the opera - I never am - but I was moved by the performances. Make no mistake, the Royal Opera fields a top-drawer cast here. In the title role, Karita Mattila, with her radiant countenance and big, shining voice, wonderfully conveys the woman who, for all her playfulness, audacity and many suitors, knows there is only one man for her. He, Mand-ryka, is played by Thomas Hampson - all flowing locks and black furs - who delivers a commanding and funny performance that brilliantly balances the apparent contradictions of the character: bluff countryman and incurable romantic. You feel the strength of the handshake in his voice, the irrational passion in every phrase he utters. Together, they are dynamite - good news for what remains of the work's credibility.

Not to be outshone is Barbara Bonney in one of her very best roles as the unhappy Zdenka, her character's desperation etched in every stratospheric phrase. The object of her desires - the sinewy Matteo, played by Raymond Very - doesn't look twice at her when she's dressed as a boy. But let's not go there.

In the pit, Christoph von Dohnanyi and the Royal Opera Orchestra make a meal - a banquet - of Strauss's luminous counterpoint. You may not like what you see, but you'll love what you hear.

To 12 June (020-7304 4000)