OPERA / Sight unseen: Anthony Payne hears Wagner's Tristan in concert at the South Bank

The case for the concert performance of opera seems especially strong at present, not only because it lets us hear neglected works that would not be economically viable on stage, but also because it allows us to experience an opera's musico-dramatic world without the distortions that have become endemic to our producer-dominated operatic world.

Generally speaking, the more psychologically inward the drama and the less reliant on physical action, the better suited an opera is to the concert hall. Certainly Wagner, who in a work such as Tristan und Isolde developed to new limits the art of psychological revelation through music, can thrive in that milieu.

The outward plot of Tristan is almost laughably simple: hero and heroine fall guiltily in love, are discovered, forced to part, and are finally reunited in a mystic union of love and death. But the emotional narrative is of unimaginable richness, and it requires chiefly the orchestra for its unfolding rather than scenic effects. Certainly in the performance under Franz Welser-Most at the South Bank last Wednesday, it made perfect sense to the ear with hardly any attempt at staging.

Given its unique role in Wagner's dramatic scheme, the orchestra's presence on the platform offers special opportunities, and the responsiveness of the London Philharmonic to the music's highly sensitised textures was one of the evening's most rewarding features.

There are obvious drawbacks to a platform set-up, however, since the balance between voices and orchestra imagined by Wagner for something like the acoustic he was later to create at his own Bayreuth theatre cannot be achieved in the concert hall. Give the orchestra its head, and the voices have to battle for a hearing; tone down the sound, and emotional intensity is lost.

Here all the singers suffered at one time or another, but Elizabeth Connell sang bravely as Isolde and grew in stature up to her final, radiant 'Liebestod', while Della Jones projected with finely centred tone as Brangane. The men were less impressive: Heinz Kruse's Tristan struggled in his final scene, although he achieved heroic moments earlier, while Curt Appelgren lacked the weight of tone to bring nobility to the role of Marke. David Wilson-Johnson was a suitably bluff Kurwenal.

The final element in a complex pattern of pluses and minuses was Welser- Most's shaping and pacing of the work's vastly complex dramatic and symphonic structures. After a beautifully gauged prelude, Act 1 went well, but thereafer there was a tendency to push forward too hastily. Significant portions of the love duet needed a broader flow, and this would have allowed the singers, as well as the music-drama, breathing space.