Musik Theater im Revier which opened in 1959, with airy glass fronted foyers dominated by Yves Klein blue sculptures and a 1000 seat auditorium, offers 200 performances of opera, ballet, symphony concerts and musicals a year with a resident ensemble. Here it ambitiously programmed a new production of Tristan und Isolde with Bayreuth regulars Catherine Foster and Torsten Kerl in the title roles. Intendant and producer Michael Schulz first persuaded Catherine Foster to sing Wagner in his Ring production when she was a member of the Weimar ensemble and she is now the reigning Brünnhilde of the current Castorf production at Bayreuth, and a leading dramatic soprano in Berlin, Washington and Barcelona.

Foster last sang Isolde in Nice six years ago and her return in the role drew an audience from across Germany and abroad. With her regal bearing, in flowing Liberty-style costumes, she dominated the stage both in the raging, foot-stamping, vengeful scorn of Act 1 and the rapture of Act 2. With fearlessly clean attack on the top Bs and Cs of her Narration and anticipation of Tristan's Act 2 arrival, her full, even dramatic soprano also encompassed lyrical tenderness and vulnerability. Some brief verbal insecurity may be evidence of the recent lack of performances in the part.

Torsten Kerl, most recently Tristan at the Theatre des Champs Elysées, took until the Act 2 love duet to strike form, his tone initially occluded and restrained. With the customary cut in the duet it is understandable that Kerl was pacing himself in anticipation of the demands of Act 3, which he sang with searing frenzy.

Phillip Ens, the guest Marke, was gravelly of voice with some insecure pitch but was poignant in the last scene. The other parts were taken by experienced and younger ensemble members. Almuth Herbst was a gently solicitous Brangäne, pouring her mistress calming cups of tea, and floating a beautiful Act 2 Watch. Urban Malmberg was a supportive Kurwenal, somewhat rusty vocally. Piotr Prochera was a notably creepy Melot.

Those expecting an extreme Regie production style from Schulz would have been surprised by the naturalistic narrative of Act 1, with a split level stage with Isolde's cabin holding the trunks, hat boxes, rugs and tea service of a 19th-century lady traveller. The direction was clear and illustrative, and it is some time since Wagner's explicit stage directions after the drinking of the love potion from a golden bowl were followed with so much trembling and clutching.

The following acts became progressively more abstract in a muted clean-lined colour scheme with the second set in a series of revolving rooms, as the lovers explored the nature of their beings and passion through innocence to abandon. Moving from a night nursery where a young boy and girl played with their dolly and teddy, through a series of mirrored chambers to the climax where a pair of young adult extras made athletic, if discreet, love beneath a duvet, stared at by Marke's voyeuristc retinue. The final act took place on a bare white stage divided by black shutters, which opened to reveal a stage-high sail and a reflective black menhir-like plinth towards which the solitary Isolde walked after her final transfiguration.

The orchestra under its chief conductor Rasmus Baumann lacks, at present, the experience for an idiomatic full Wagnerian sound, with some poor intonation initially, especially from the relatively small number of strings, but with characterful woodwind playing and blazing brass. Missing the overall span and structure, the conducting was still empassioned, especially in the opening of Act 2 and the Liebestod.

The audience reaction was jubilant with just a few token boos for the production team. Given the inordinate demands of mounting Tristan und Isolde it can be counted a success for a regional theatre in a city of 250,000 to mount a convincing production. In April the title parts will be taken by Gerhard Siegel and Yamina Maamar. There is no doubt that Catherine Foster's Isolde amply fulfilled expectations and is worthy of the world's great stages.