Das Rheingold, Royal Opera House, London

And so it begins. The low E-flat sounding from the depths of a blacked-out auditorium, the mysterious undulation of horns. So begins the wave-like motion that tells us where we are: on the bed of the Rhine at the start of Wagner's Der Ring des Nibelungen.

The importance of the moment was evident in the concentration of the playing. The Royal Opera Orchestra were sweating blood to get it right for Antonio Pappano and the gods smiled on them. I believe "world class" is the phrase.

The gods on stage were in pretty good shape, too. Keith Warner's production now gets to reveal how its thinking melds into a coherent whole. To me, Warner is a bit of a Loge, the wily god of fire – wonderfully played (and sung) in this staging by Philip Langridge.

Warner's visual symbolism, in collusion with designer Stefanos Lazaridis, isn't too much of an imaginative stretch. Wotan and Fricka's black marble penthouse is a window on the world with a view of the newly built Valhalla. To incorporate that window idea into the Tarnhelm, the magic helmet that conceals and transforms, neatly draws the two ideas together. Appearances, you see, can be deceptive.

So why turn Nibelheim into a grubby laboratory full of human lab rats and flayed cadavers? Because humanity is stripped and debased here. It's a chilling moment when Alberich (Peter Sidhom, excellent), who has renounced love but not lust, has his way with a heavily restrained female.

Warner even gives us the back-story. We see how Wotan gave his eye in exchange for wisdom; we see the branch of the World Ash Tree transform into his spear – essentially, we see the primitive turn into a model of respectability. Wotan and Fricka are the classic Victorian couple. At least that's what she (Rosalind Plowright, superb here) wants him to be. But, in John Tomlinson's elemental Wotan, we sense the restless man within the god. Tomlinson owns this stage.

And Warner has Wotan turn back from the entry into Valhalla, discard his god's mantle of power and sneak off for a night or two on the tiles. He will seek out Erda, who will sire his daughter Brünnhilde, then he will father Siegmund and Sieglinde with a mortal woman. No wonder Fricka's taken up knitting. The scene is now set for Die Walkure.

To 26 October (020-7304 4000)