OPERA: There's a world inside their wardrobe

There's a moment in Act 1 of Wagner's opera where Siegfried demands to know the truth about his real parents. He wants answers, he wants to understand, he wants to grow up. In Richard Jones's new staging, Mime, the dwarf, his ill-intentioned guardian, agrees to tell him the whole story, the whole truth. But as he does so, he blows the dust off a mysterious box. Inside is another, and another, and another. All of them empty.

I imagine that a large percentage of Monday's Covent Garden audience will have seized upon this moment as a metaphor for the entire production. But the reverse is surely proving to be true. As each new box is opened, as each new instalment of the Jones Ring is placed in context, its quirkiness becomes more logical, its symbols more accessible, its surprises more intense. In Jones and his designer Nigel Lowery we have two inquiring and capricious imaginations. Their staging may resemble the playroom of a precocious child, but through that child's eyes, anything is possible.

And so their colours, shapes, and symbols begin to add up. And there is magic in them. The strange blue figures that were a living, breathing Rhine in Das Rheingold and the tree of life in Die Walkre are here wild beasts and woodbirds. The Gods are still seen blindly following their star - Christian symbol in a pagan world. Wotan, the Traveller, has wandered far and lost his way. He is quite literally a blind man. Siegfried is but a boy at heart - orange shorts, a satchel; but when he kills the dragon Fafner, he becomes a man, he acquires knowledge, he wins his long pants.

Jones has a way of taking everyday ideas, everyday objects and surprising us with them. He's an ingenious improviser. And if you go into his work without preconceptions, you start thinking like him. The riddle scene between Mime and the Traveller is clarified in simple theatrical terms through the use of a bare light bulb. Wotan, "God of Light", unscrews it, but the bulb remains illuminated, symbol of his enlightenment. The cord represents bondage and a noose for the loser. And then there are the wardrobes, after C S Lewis: refuge for the Gods but, for Siegfried, the door to a new life, a new world, free of Mime.

Sometimes Jones will take his lead from a line of text. As in Act 2, where Alberich's reference to the Traveller "outlined in shadow" is Jones's cue to enact the whole scene in shadow-play: god and dwarf are indistinguishable. Other times Jones takes the text by surprise. His recurrent image of the dragon - a childish sketch cum primitive cave-drawing, seen now in silhouette - is not the image that finally confronts Siegfried at the mouth of the cave. That is much more disturbing. Siegfried's worst nightmare, in fact: a giant Mime-like mother-figure in a bloody apron with the head of a Hallowe'en pumpkin. And all it wants to do is kill him with kindness. A little touch of theatrical genius, this. It goes right to the heart of the piece, and does so with Jones's characteristically mordent humour.

As ever, Jones concentrates his performers. Graham Clark's Mime, an androgynous leprechaun with the primness of a governess and the enunciation of a psychopath's knife, is a marvellously mercurial creation - the perfect foil (and resistance) to John Tomlinson's weathered Traveller. Siegfried Jerusalem's Siegfried, brave and wholehearted, didn't deserve to suffer the ignominy of his voice giving out on him at the climactic moment of Act 1. But it's a sign. The late-starter has still had a good innings. His Brnnhilde went to sleep a Valkyrie and awoke a Disney princess in the shape of homely Anne Evans. And she was radiant. It isn't a big-personality voice, not one to set the house alight. But it's honest and honestly used, and she knows how to sing more with interest than capital.

Bernard Haitink continues this great Ring journey with momentous results, from the crepuscular lower depths of the forest to those eternal crescendos of light on the top of the world. But, as Anne Evans opened splendidly to her final top C, I wondered how many more minds had opened to Richard Jones's staging.

Edward Seckerson