Le Vin herbé is not an opera, it’s a “secular oratorio”, composed by the Swiss composer Frank Martin between 1938 and 1941 for 25 chorus members, eight soloists, two violins, two violas, two cellos, a double bass and a piano. It’s an interpretation of the medieval legend of Tristan and Iseult, the tale of adultery between a Cornish knight and an Irish princess in which love and death embrace. Martin was at pains, as Michael Tanner points out in his excellent programme essay, not to be compared with Wagner – which in itself invites comparisons.
Where Wagner was grand, dramatic and compendious, Martin is intimate, incantatory and contained, and his oratorio begins with the chorus delivering what, if you did not know the story, might be seen as a colossal spoiler: “They died on the same day, him through her, her through him.” It’s a line that draws attention to one of the several challenges of staging this work: lack of emotional variety. When a story starts with doom, there is nowhere to go. In this anguished set piece, one of Iseult’s first words is “disaster”.
Director Polly Graham has come up with the appealing idea of placing the musicians centre stage – perhaps in recognition of the fact that it’s the music that counts most. The chorus is dressed in black, the soloists mainly in lighter costumes, and the look is classical, elegant and unadventurous. The difficulty is that the central island of musicians sometimes makes the action seem marginalised, although Graham partly solves this by placing some encounters on a metal platform above the stage. Conductor James Southall brings the score to life with zest, and there are moments when his connection with the soloists is exciting – almost as if he were a member of the cast himself. Yet one cannot help but note the contrast between his animated presence and the static way everyone else has, for the most part, been directed to stand and deliver.
Iseult’s mother, performed with aplomb by Catherine Wyn-Rogers, oversees the making a potion (are magic potions ever a good idea? This one symbolises the perils of parental intervention). The strings keep up an ominous commentary, like the information that comes with medicines, warning of potential side effects. Caitlin Hulcup as Iseult sings with unassailable intensity, especially in the moment she crosses the stage saying she always loved Tristan most. Her voice is in stark contrast to what happens to her – it seems that it could survive anything. As Tristan, Tom Randle is also excellent, with precise diction and pathos. When he sings “Iseult is your wife and she cannot love me”, it is powerful and affecting. A panicky piano agrees.
But there is a perverse disdain for the literal here – performers frequently overlook the libretto. So we are told that one of the lovers is drinking the potion, but this (easy enough, after all, to execute) is ignored, to take one of several irritating examples. Mark, the King of Cornwall, is tremendously played by Howard Kirk. His sorrow and shock at the sight of the lovers, with a sword between their sleeping bodies, is one of the most moving moments in the evening. On waking, Tristan drops the sword (that King Mark has swapped for the original) with an audible clunk. A little later and he is running to and fro shifting metal chairs across the stage to illustrate his febrile condition, making a din that interferes with one’s enjoyment of the music.
The WNO chorus does sterling work, and some of their acting is great: at one point they dance together with thin-stemmed glasses in their hands, playing out the story as well as singing it. But Graham and her cast have taken on a pretty impossible task. The proof of the potion is in the drinking, and this single draught of an evening (straight through in just under two hours) is marvellous to listen to but not easy to swallow.
• At Milton Keynes theatre, 21 March, then touring until 25 April
