Edinburgh: The best of two minds: Raymond Monelle and Paul Taylor disagree over Robert Lepage's operatic debut

Sometimes a production can make you understand, all at once, what an opera - even a familiar one - is all about. Bartok's Bluebeard's Castle is a piece one sees from time to time but which has always seemed problematic, too much concerned with inner realities to be turned into real theatre.

Canadian Opera's Bluebeard accomplishes the horror almost without departing from Bartok's stage directions: each door, as it is opened, produces only a gleam of light, flashing, flickering and rippling, the door of the garden filling the scene with shadows of foliage, the lake a flowing stream of water in which Judith's hand splashes in time with the orchestra's sobs of misery.

With his reputation for high tech, the producer, Robert Lepage, might have used the work as an excuse for spectacle, especially as his lighting designer, Robert Thomson, is a lover of cavernous gloom and bright spots that lift the figures out of darkness. But in fact the real insight came in the relations of the two characters. Bluebeard, sung with dark intensity by Victor Braun, was a lost and defeated man, finally broken by the inevitable opening of the seventh door; Jane Gilbert, noble and opulent-sounding as Judith, kept her distance from him, pulling away the hem of her dress as he clutched it in pathetic desire.

This staggering opera - here is the revelation that transformed my view of the work - is about tension, the tension between men and women, the impossibility of their ever coming fully together. When Braun and Gilbert finally took hands and smiled for their curtain-calls, it brought an overmastering relief.

Lepage's vision was made all the clearer by an orchestral commentary that moved deliberately, stealthily, as conductor Richard Bradshaw used the score's richness and harmonic clarity to underline its relations to French music.

This is an outstanding orchestra, and its contribution to Schoenberg's Erwartung was equally telling. Yet this 'monodrama' proved unstageable, as I had always suspected. It is a golden rule that the director must not impose his own interpretation on the work or limit its ambivalence; Erwartung is so ambivalent and so untheatrical that Lepage could only interpret it as a psychotic dream, using the high-tech dimension to conjure up surrealist images and place the action, such as it is, in an analyst's consulting room.

His psychiatrist, who eventually turns somersaults and reappears perched on a high wall; his dead lover, who gropes through the wall like a figure in Magritte; his wandering moon, which drifts from the backcloth to the front scrim and back again - all suggested that this was a story about the Freudian unconscious. It was grisly and disturbing but somehow a debasement of Schoenberg's enigmatic score.

Rebecca Blankenship sang the tormented solo part with unrelenting stress, elegiac rather than crazed. This production was visually astonishing, but an aberration, confirming that Erwartung is really a concert work.

Robert Lepage has always struck me as one of the great solipsists of contemporary theatre. All his productions feel as if they are imprisoned under the giant bell-jar of his own visually ingenious but emotionally stifling subjectivity. This poses few problems when the shows are self-devised and /or solo works such as Vinci and Needles and Opium. But his recent mud-bath staging of A Midsummer Night's Dream at the National, which obliterated any distinction in the play between dreamworld and real world, suggested that Lepage is not overly responsive to the promptings of another artist's imagination or to the restraints of fact.

For his immensely impressive debut as an opera director, however, he has chosen two one-act operas that are ideally suited to his strengths. The essential drama in both Bluebeard's Castle and Erwartung is an interior one. The gothic castle in the first is, to all intents and purposes, cranial: it's as though the struggle between Bluebeard and Judith is taking place in the hero's skull. Erwartung, which follows, is an anguished monodrama, the crazed, confused outpourings of a woman searching in a forest for a lover she may well have killed in sexual jealousy.

Lepage's audacious staging of this second work may violate the letter of Schoenberg's precise stage directions but it arguably liberates the spirit animating the piece. Instead of a naturalistic forest, a shifting dreamscape; instead of a lone protagonist, a young (initially straitjacketed) woman whose solitary burden of consciousness is emphasised by the figures dredged up from her mind who tumble about weightlessly as if in a picture by Magritte.

Some may think that Lepage's visualisings make too explicit the contradictions in, and the defensive strategies of, the girl's tortured mind. But partly thanks to Rebecca Blankenship, whose wonderful scalded voice hurls itself to the end of the girl's tether, the directorial interventions always seem to be in the cause of pity rather than mere cleverness.

The staging of Bluebeard's Castle, with its restrained lighting effects a disappointing index of what lies behind each door, is powerful but not on the same level of imaginative appropriation. It's with Erwartung that Lepage decisively enlarges his emotional range.