Opera: Siegfried/Gotterdammerung Theatre Royal, Norwich

There would have to have been a dramatic downturn in the quality to dampen the enthusiasm of the Norwich audience for the continuing Ring cycle of the Norwegian State Opera. After Rheingold and Valkyrie, they began to exude a rapport of shared experience and a torrent of bravos was heard after each act; on Wednesday, unfortunately, before the music of the Act 2 had quite finished.

But the enthusiasm was justified, even if Wednesday's Siegfried was less consistent than what had gone before.

Knut Skram sang the role of the Wanderer. His voice is rich and resonant but the performance did not entirely convey the conflicting emotions of a doomed god who wishes to cling to power but knows he must renounce it.

Best performances came from Niebelheim: Arild Helleland's sharply characterised and excellently sung Mime, and Hartmut Welker's equally fine Alberich. More problematic was Edward Cook in the title role, who for most of the evening promised a less than heroic Siegfried, given to shouting his high notes. Things improved somewhat with the love duet at the end of Act 3: Carol Yahr has a good dramatic presence and makes an attractive Brunnhilde, though neither her voice nor Cook's seemed to possess the sustaining power that these roles demand.

Give or take the odd eccentricity, Mike Ashman's production did not interfere too much with Wagner. Things changed fairly dramatically however with Saturday's Gotterdammerung. Siegfried's Rhine journey brought him straight into what could have been any time from the 1920's to the 21st century, for the curtain rose on Act 1 to a Gebichung Hall that was all steel and glass, a Gunther who might have strayed out of Star Wars, and a Hagen who could apparently locate Siegfried on the Internet and who issued instructions to the Vassals through microphones.

The justification for all this is perhaps to convey events taking place on a vast time scale, but it all seemed eccentric and inconsistent: Vassals who paraded with rifles and hunted with crossbows and, by the end of Act 3, a Gebichung Hall that was practically an empty stage, reverting to any time, any place.

After a while, one stopped noticing and was once more absorbed in a Gotterdammerung that maintained the high musical qualities of this cycle. The Prelude produced excellent singing from the three Norns, and Rosemarie Lang was a very fine and dramatic Waltraute. Gudjon Oskarsson conveyed all Hagen's menace, keeping up his spirit of hatred literally with a quick shot from a hip flask before his worst machinations. Edward Cook's Siegfried was initially on better form, although visibly flagging by the end of the evening, while Carol Yahr's Brunnhilde grew in stature throughout the performance.

It would have been too much to expect the greatest Wagnerian voices, although musically there has been nothing that has detracted much from the overall high standard. The greatest credit must go to conductor Heinz Fricke who has paced the music so admirably: clear textures, always perfect balance, and no hint of self-indulgence; and to the orchestra of the Norwegian Opera who have responded so magnificently. A pity, after such a success, that there was only one cycle: after some 15 hours' music, there might even be a few who would echo mad King Ludwig and say let's hear it all again.