Michael Berkeley’s For You, set to words by Ian McEwan, and premiered by Music Theatre Wales at the Linbury, Covent Garden, is not the first opera to depict a composer. One thinks of Pfitzner’s Palestrina, Maxwell Davies’s Taverner, the Composer in Strauss’s Ariadne auf Naxos, Dov in Tippett’s The Knot Garden. Along with the two latter characters, Berkeley’s Charles Frieth, pre-eminent British composer of his day, is fictional, which means that, unlike Davies with his use of a John Taverner In Nomine, Berkeley is not able to exploit existing music made by his character, but must presume to compose “great” music on his behalf. A nice little tease, and one of several that animate this fascinating and enjoyable work, cast by McEwan as a kind of drawing-room tragedy, but transformed by Berkeley into a genuine music drama, albeit for chamber forces.

The two have collaborated before — on the oratorio Or Shall We Die?, dating from 1982, when McEwan was known for his short stories but barely yet for novels. The opera libretto alludes to several of his more recent books, such as Amsterdam, in which a famous British composer is one of the two main characters, and whose plotty, melodramatic ending predicts the opera’s, and Saturday, whose reflective surgeon protagonist is echoed in the libretto’s Simon — and a grim notion of “atonement”, title of a third novel, underpins

For You. McEwan has produced an elegant, two-act structure, in a rhythmic, clear prose that borders on verse and is manifestly open to the idea of music — there are numerous cues for ensembles, including tutti finales in the classical manner — without foregoing literary appeal. Indeed, he insisted on surtitles so that we should not a miss a word. But unlike so many recent librettos of the “sung play” type, his is not wordy.

The story is that of an egotist’s undoing. Charles, whom we see at the start on the platform edge, about to rehearse an orchestra — the very pit band, in fact, also being conducted by Michael Rafferty — has treated people badly. He is cruelly demanding of his secretary (Christopher Lemmings), and has for years neglected and betrayed his rich wife, Antonia, who is seriously ill. Both his brusqueness and womanising are immediately revealed as he publicly dresses down the young hornist (Rachel Nicholls) for playing a wrong note, then seduces her by promising a solo in his new work, Demonic Aubade. He is given pause, though, by the surgeon Simon’s undue attentions to Antonia — he has long been secretly in love with her — while the Frieths’ Polish housekeeper, Maria, is convinced that her undeclared passion for Charles is being reciprocated in coded behaviour.

It could be a bedroom farce, but it turns nasty when Maria, thinking she has been encouraged by Charles to rid him of Antonia, rips away her life-support tubes as she lies recovering in an intensive-care ward, and implicates Charles as the murderer. Just as he is rehearsing Demonic Aubade, the police appear and take him off. Maria’s plan, her gift “for you”, as he learns at the end, is to get him into a prison cage, safely away from other women, and visit him constantly, and reduce him, as it were, to the mediocrity of a caring but demon-free, “gift”-free, relationship. It is a version of the fate of that operatic libertine Don Giovanni, as Charles’s last words indicate: “I am already in hell.”

On the page, all this has much potential for dramatic caricature, but Berkeley has moved the situations to a level where McEwan’s moral diagram becomes expressive. Though Maria is evidently a psychopath, her aria of devotion to Charles is the score’s most beautiful passage, marked by a harp ostinato and sung passionately at the Linbury by Allison Cook (who is far from being, as the libretto specifies, “ungainly”). One is made to feel for her, just as we are touched by the duets for Simon (Jeremy Huw Williams) and the hapless Antonia (Helen Williams). Most important, we feel for the supposedly monstrous Charles. In part, this is due to the warmth of Alan Opie’s wonderfully convincing portrayal, but Berkeley does meet the crucial challenge of devising music for the Demonic Aubade that allows us to take seriously Charles’s claim that “History will forgive my ways because / My music out-stared the sun”. When, after this dizzying avowal of aesthetic supremacy, two policewomen banally bob up, Charles is like a Prospero enraged at being reminded of the fact of Caliban.

Berkeley’s score, brilliantly despatched by the 14 players, is full of zest and humour, with sly quotes from Mozart, Britten and his own Oboe Concerto, and a blues stretch recalling The Knot Garden. McCarthy’s staging, using Simon Banham’s suspended wooden-board designs, is simple but very deft. Catch the performance tonight or in Cardiff or Durham later this month.

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