Tristan und Isolde, Welsh National Opera

Welsh National Opera has a good track record with Wagner. Its Meistersinger of two summers ago is already the stuff of legend (and alas not likely to return to reality); farther back one recalls a more than respectable Parsifal, a notable Ring cycle, and an old Tristan under Goodall that’s still talked about in hushed whispers.

This more recent Tristan, itself almost two decades old, belongs strictly to a new era. Nowadays WNO does original language and books international singers, which in theory – if not always in practice – lifts its productions out of the provincial league. It also has the Millennium Centre, a kind of poor man’s Bayreuth, with superb acoustics, a wonderful spread of sound, and first-rate sightlines. Top singers, one suspects, enjoy singing here; and top singers are often to be heard in the Land of Song – even, from time to time, Welsh ones. The current revival sports at least two, possibly three, who would be an adornment to Bayreuth.

Ann Petersen is immediately perfection as Isolde, and mostly she stays that way

It has its problems, too; but what Tristan doesn’t? In the Master’s own theatre they’ve virtually given up on those aspects of the work that were demonstrably closest to his heart: the sense in which the stage picture is a direct projection of the spirit and content of the music. By contrast, Yannis Kokkos’s staging in Cardiff is orthodox. It dresses its characters out of the medieval wardrobe and locates them in “correct” but uninsistent settings: a ship (or at least a thing with a sail), a sort of garden with a house wall and a light, a rocky coast.

Mostly it leaves them space to move and relate, which, under Peter Watson’s guidance in this revival, they do pretty well, though not without the odd crasher – literally, when the lovers collapse with one accord after drinking the potion, ruining the whole symbolic idea that the potion opens their hearts because they believe it will shortly kill them. But I shan’t complain about a production that generally respects the score so well and – not least – that shows us the front curtain during the prelude. For once, no Morold ballet, no tableau vivant of King Mark dispatching Tristan to Ireland, no dumb show of Wagner seducing Matthilde Wesendonck. Just a curtain, and that incomparable prelude, beautifully played.

When the curtain does go up, at precisely the moment indicated in the score (help!), we’re treated to half an hour of some of the most beautiful Wagner singing I can remember, starting with Simon Crosby Buttle’s Sailor (placed, though, too far backstage, as incidentally is his Shepherd’s cor anglais in Act III). Ann Petersen (pictured above right with Ben Heppner, image by David Massie) is immediately perfection as Isolde, and mostly she stays that way. Hers is a lighter, more lyrical voice than the conventional Wagner soprano, and she floats Isolde’s lines as if they were Schubert, lovely and effortless, though with ample power when needed, hardly ever sounding forced.

One might sit back, shut one’s eyes and simply listen. But one would miss a great deal, because this is a Wagnerian who can act, with presence and total engagement, and she even looks the part. When Brangaene enquires: “Who could see Isolde and not die happy?” for once one doesn’t wince at the irony. Above all, Petersen knows how to carry her looks into the role; her Isolde is a creature who loves and who one can imagine loving, something that in this work usually has to be supplied by the imagination.

As for Susan Bickley’s Brangaene, it’s enough to say that she is not upstaged. She, too, is a soprano who can treat Wagner as pure vocal line. Later, in her tower in Act II, she captures unforgettably the haunting fusion of time suspended but about, catastrophically, to move on – a stretch of score I always like to think captivated Debussy, though of course he misread it (as Harold Bloom would say) to suit himself.

Bickley, too, is good on stage, a slightly fragile presence but not without a certain self-deprecating authority: a companion as much as a servant. She and Petersen are a match made in heaven, compulsively listenable to and watchable.

It is, at present, a somewhat cautious Tristan. The frenzy is perhaps waiting in the wings

It would be straining goodwill to say the same of Ben Heppner’s Tristan or Philip Joll’s Kurwenal. Joll, who sang Wotan on this stage 30 years ago, is still a fine, somewhat ageing squire to behold, but his vocal line betrays him a little too often for comfort. Heppner has his moments, and survives the third act, curiously enough, more impressively than the second, though the survival is relative in both cases. Too often the voice splits or the tuning goes; and once you start fearing for a tenor in this part you’re done for where suspended disbelief is concerned. Heppner’s figure is against him, too. Enough said. The best male singing comes from Matthew Best, a moving, steady-voiced Mark, and from Simon Thorpe’s Melot, the ultimate walk-on part but often, unfortunately, cast too weak.

The orchestral playing is beautiful throughout: much exquisite solo playing, a few moments of dodgy wind tuning – but Wagner does not make things easy (how can some of these chordings have sounded in Munich in 1865: music completely outside the players’ experience?). Whether Lothar Koenigs is yet utterly at home in this score is an open question. Everything is well under control, but the music’s contour is low, and its natural surge slow to come. It is, at present, a somewhat cautious Tristan. The frenzy is perhaps waiting in the wings.

• Tristan und Isolde at the Wales Millennium Centre on 26 May and 2 June, then at the Birmingham Hippodrome on 16 June