OPERA / The undiscovered country: Edward Seckerson on Welsh National Opera's new Tristan und Isolde

SIR CHARLES Mackerras led an inspirational Tristan und Isolde in Cardiff on Saturday. Nothing less will do, of course. An uninspired Tristan is no Tristan at all; great performances of this piece are not manufactured, they evolve. You don't counterfeit Wagner's eternal longing. But I do believe Mackerras came close to a great Tristan on Saturday. One could feel that very special alchemy in the first tentative soundings of the love-potion motif, and in the yawning fermatas - the still, silent voids which already symbolise the gulf between Tristan and Isolde. Mackerras was at once spacious and urgent.

It is the sustained rapture of this supreme score, a sense of the infinite as well as the immediate, that eludes all but the most gifted few. Mackerras and his heroic WNO orchestra were gripping and infinitely flexible in both action and introspection. As overwhelming in their way as the tumultuous physical releases, the never-quite-fulfilled climaxes (and in the New Theatre's grateful acoustic those climaxes overwhelm the audience, not the singers) were the long searching wind solos - not least among them Wagner's eloquent bass clarinet - guiding our way in to the darkest recesses of the opera's interior world.

That interior world, the psycho- dramatic core of this most intimate epic, is supremely testing of any producer and designer. Yannis Kokkos served both functions here in a simple expressive unity. His modest show is not so much designed as sculpted, a degree of movement achieved in the sensuous sweep of a sail or wall or ramp; light, colour, texture play their part and his characters are figures in that abstract landscape. Kokkos has spoken of striving for a kind of 'spiritual choreography' - meaning that he gives his singers the freedom of stillness. Act 2, the opera's still centre, the illusory 'night of love', is simply achieved through a series of slow 'dissolves', the lovers variously entwined in rather beautiful portrait-like poses. A double- proscenium hints at a kind of double-perspective, most effective in Act 1, where Isolde views Tristan at the rudder of the ship through a gauze of unreality - so near, yet so far. After drinking the fateful love-potion (where Kokkos has them quite literally awaking as from a deep sleep), the gauze flies out. Paradoxically, the potion-induced illusion suddenly achieves a frightening clarity.

Anne Evans was singing her first Isolde, here, Jeffrey Lawton his first Tristan. Neither could have given more of themselves. Evans easily surpassed anything I have previously heard from her. Her singing has been enriched, intensified by experience. She was always a textbook singer, making the most of a modest instrument, but she is singing more on the emotion now. Her generous, womanly portamentos embraced the line, the small house flattered her determined but unspectacular top. She was proud, ardent, moving. Lawton's Tristan could hardly have made more of his attributes, either. The heldentenor colour is authentic, the sound less than beautiful, though the placing of key phrases, the sensitivity and humility of his lyric singing in Act 2 could almost have had one thinking it was. His Third Act was courageous, unstinting, with Richard Paul Fink the most effective and fresh-voiced Kurwenal. Della Jones's incisive, impassioned Brangane merits more than this brief mention, as does Peter Rose's King Marke, a handsome voice of natural compassion.

A special WNO evening, then: the sense of shared experience in the house was palpable as the light faded on Isolde's Liebestod, leaving the image of her white dress on the retina and Wagner's orchestra to sign off in quiet sublimation.

Further performances: Sat 20 Feb, Sat 6 March, New Theatre, Cardiff (0222 394844); Sat 13 March, Hippodrome, Bristol (0272 299444); Sat 27 March, Mayflower, Southampton (0703 229771); Sat 3 Apr, Apollo, Oxford (0865 244544); Thu 15 Apr, Hippodrome, Birmingham (021-622 7486)

(Photograph omitted)