Must every Michael Berkeley opera be born with an accompanying drama off-stage? Nine years ago his half-completed score for Jane Eyre was stolen and never recovered; it had to be rewritten virtually from scratch. This year, the first performances of Music Theatre Wales’s For You, his collaboration with Ian McEwan and the author’s first libretto, were cancelled when the singer playing the antihero withdrew at the last minute.

So, enter at last the distinguished composer-conductor Charles Frieth, now clad in the healthily robust baritone of Alan Opie. His marriage to the rich Antonia (Helen Williams) has atrophied. The music that shot him to fame when he was young no longer appeals. Soon enough, he is bawling out a fruity horn player for one wrong note before chasing her into bed and rewarding her with an extra solo in his latest premiere. “An insertion he needed to make,” snipes his secretary from the sidelines.

This is pithy, witty stuff — and thank goodness for an opera libretto that knows when to quit: McEwan skewers these characters to his blackly comic canvas in typically concise fashion. And then he springs a deadly trap: Charles is so egocentric and controlling that he fails to notice the one woman (his besotted Polish housekeeper, Maria) whom he cannot control.

But if For You has a faultline, then it’s how this macabre short story finds its connection to Berkeley’s score. Jane Eyre was close-focus and tightly written; so, too, is For You. But both pieces took too long to cleave emotionally to the drama. Berkeley’s palette — all fevered chromaticism, suspenseful ostinatos and fierce but eminently singable vocal lines — is a heady concoction. But it gallops harum-scarum around the words without helping us truly to invest in the characters. We pity or mock them. Who do we feel for? Snappy direction from the conductor Michael Rafferty and the Music Theatre Wales Ensemble aside, too much sounds like it could be cut and pasted from one role to another.

Opie is always a class act — and his crystal-clear diction undermines McEwan’s diva-ish demand for surtitles — but what he doesn’t (or can’t) do is give us much of Charles’s charisma and sexual magnetism. In fact, the character most fully explored is the Maria (Allison Cook, creepily intense but raw above the stave), who gets the benefit of the opera’s only real aria, set against the mournful strains of a harp. Michael McCarthy’s barebones production is fluid enough, but the comedy is weakly delivered and the bland Ikea-style set does little to add atmosphere.

Come the climax — Charles’s artistic credo juddering into his grim comeuppance — I warmed to Berkeley’s score, particularly when it was simply giving us the frayed genius of Charles’s own music. And I stayed convinced of McEwan’s libretto, tart to the last despite its niggling plausibility holes. But did the two belong to each other? Not sure.

Box office: 020-7304 4000 (to Nov 2). Then touring to Cardiff and Durham: www.musictheatrewales.org.uk

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