I won’t get to review the new Tristan und Isolde at Longborough this summer, and I didn’t get to review Welsh National Opera’s most recent either. Same problem in both cases – the senior critics snaffle all the plum gigs (and plums don’t get much juicier than Wagner at Longborough). I only know that – based on what I saw of the 2013 Longborough Ring Cycle – it’ll be extraordinary. Michael Tanner once told me that in his view, Longborough embodies the spirit of Bayreuth more than Bayreuth itself, these days.

Meanwhile, here’s something I did write about Tristan for Metro, in 2006 – WNO’s revival of Yannis Kokkos’ 1993 production. Mark Wigglesworth conducted, and in light of his subsequent appointment to ENO, I think what he had to say then is still of some interest.

“Since I have never in my life known the true bliss of love, I will raise a monument to this most beautiful of all dreams – in which, from first to last, love shall be completely fulfilled”. Say what you like about Richard Wagner – he was a man of his word. In Tristan und Isolde, his 1865 re-telling of the Celtic legend of Sir Tristram and Princess Yseult, Wagner created a love story so overwhelming that even he started to wonder whether he’d gone too far: “Only mediocre performances can save me – good performances will drive people mad!”

So perhaps Welsh National Opera’s Tristan und Isolde should carry a health warning. Conductor Mark Wigglesworth certainly has some sympathy: “It gets inside you, more than any other music. It’s bad for your health!” And he should know. The buzz about this revival of Yannis Kokkos’ 1993 production is coming from a pair of remarkable young Wagnerians. One is Annalena Persson (Isolde) – the Swedish soprano who stole last season’s WNO Flying Dutchman from under Bryn Terfel’s nose. And the other – conducting Tristan for the very first time – is Wigglesworth himself.

Though it’s not his first brush with Wagner. Wigglesworth conducted The Mastersingers of Nuremberg at Covent Garden in 2002. Good training? “No – It’s absolutely no use to Tristan”. Because this opera, he explains, is a very special case indeed. “Mastersingers is a very human piece, with lots of action and genuine historical characters. Tristan is much more difficult – you’re relating to the emotions rather than the characters. Even though it’s shorter than Mastersingers, the sheer intensity that you need to maintain over the whole evening is incredible. I expect it to be much more draining”.

And it turns out that Wigglesworth has, after all, been in training for the challenge. “Starting early is the best thing. I started work two years ago – though you can’t really get to grips with the structure until you’re rehearsing full acts”. But you can begin to immerse yourself in the extraordinary emotional and philosophical world of this huge work. Tristan’s plot – an eternal love-triangle – is deceptively simple. But Wagner, as he wrote the opera, was embroiled in a passionate affair, not just with a friend’s wife, but with the writings of Arthur Schopenhauer. It’s this philosophical dimension that lifts Tristan’s central love story onto a cosmic level.

Wigglesworth’s done his homework. “As a conductor, I have to be interested in the drama – I can’t make a musical decision divorced from the dramatic situation. The idea of just conducting the orchestra is impossible for me.” And he likes what he sees on stage – “I first saw Kokkos’ production back in 1993. It just tells the story; it’s very simple. It’s not a Konzept production, with a capital K”. That’s important for him. “A lot of directors hide behind complex ideas. You can get a bit bogged down, and forget that this is a great story with extraordinary music. Our job is to tell that story.”

But how – practically – do you tell a story that begins with a cry of longing and ends, nearly four hours later, in a quarter-hour musical orgasm? For Wigglesworth, the secret’s in the pacing. “From the very first note, it flows right through to the very last note. It fulfills itself, musically and emotionally, only at the very end” he explains. “You don’t want to peak too early!”

Four hours of deferred ecstasy – no wonder some listeners find Tristan und Isolde slightly more than they can bear. And yet Wigglesworth can’t contain his enthusiasm: “Wagner was just the most extraordinary musical genius we’ve ever had – even more than Mozart”. So it’s worth it? “Tristan’s the greatest love story.  Ever. And it’s told in the most romantic music. Ever. It can transform you”. There’s your answer. Why listen to Tristan und Isolde? Well, why fall in love?