First Night: Das Rheingold, Royal Opera House, London

The overture to 'Das Rheingold' is one of classical music's boldest strokes, as a single bass note slowly expands upwards into a vast major chord, whose eddying ramifications remain static and unchanged for 136 bars. Under Valery Gergiev's febrile beat, the Mariinsky orchestra beautifully realises this effect, and for the next 150 minutes faithfully reflects every colour-shift in this opera's majestic musical journey.

As the first full Russian production of 'The Ring' since 1914, this globe-trotting show - which came to Cardiff two years ago - has a lot riding on it. It's been a roller-coaster from the start, going through a series of directors, the latest being 24-year-old Alexander Zeldin. And while not even Bayreuth puts its performers through the ordeal of all four operas on successive nights, this is what Gergiev, with typically bull-like impetuousness, is doing with alternating casts.

As he's been explaining to anyone who will listen, he's sought to distance himself from the usual clichés, replacing the original Nibelung sagas with the myths of his native Ossetia, whose Nart gods make neat parallels for Wagner's Fasolt and Fafner. Some see the cycle in strictly Freudian terms, while others see a Marxist critique of capitalism. In the Nineties it was fashionable to present the gods in sharp suits and dark glasses. Zeldin, who has 're-imagined' the story, apparently regards the curse of the stolen gold as a metaphor for our despoliation of the planet. Gergiev has also brought in the video artist Sven Ortel, to temper the heaviness of George Tsypin's original designs.

Wagner intended his operas to be a feast for the senses. The scene which first assails our eyes might have come out of a Fifties panto, as three pixie-ish Rhine-maidens chastely cavort while a dour Alberich (Nikolai Putilin) looks on without evincing much sexual interest; the Rhine consists of writhing dancers under a big silk sheet. For Wotan's swish new residence in Valhalla, four giant twiglets float down into view, more Egyptian sarcophagi than Narts. The domestic squabble between Wotan (Evgeny Nikitin) and Fricka (Larissa Diadkova) is excellently sung, but oddly stilted; all the characters stand about like trees until god-of-fire Loge (Oleg Bashov) comes on, and he can move as well as sing.

And this is all the staging we get. When Alberich turns into a snake, back come those dancers under their sheet. Vadim Kravetz and Gennady Bezzubenkov as the giants Fasolt and Fafner prove quite unable to transcend the puniness of their costumes, with the latter having a horrid night: first his skirt slips down and has to be taken off, then his headdress catches on a twiglet and pushes down over his eyes, making him stumble about blindly. Their cartoon abduction of the goddess Freia (Zhanna Dombrovskaya, in lovely voice) adds another touch of inadvertent comedy.

Despite much radiant Russian singing, with Evgeny Ulanov's Donner and Zlata Bulycheva's Erda both outstanding, this production is simply woeful. There’s no imagination in it, nor any shred of theatricality. I never thought to see the day, in these concept-crazy times, when I would find myself complaining about an opera without a "concept", but by God this show needs one. And how ironical that this should be on the same stage which - when the Royal Opera is in residence - houses Keith Warner's brilliant production of this work.

Gergiev is famed for his compulsion to control everything he touches, but he's emphatically no Diaghilev, and should henceforth confine himself to conducting - otherwise it's the downward slope. Meanwhile, if the rest of this 'Ring' is of the same abysmal standard as its opening production, he should scrap it. A concert performance would have been infinitely preferable.