Seven Angels, The Opera Group, Cardiff

Glyn Maxwell’s last opera libretto, as far as I know, was Elena Langer’s The Lion’s Face, about Alzheimer’s – a worthy topic indeed. His latest effort, of which the above is the best I can do by way of synopsis, is even worthier, since if Monday’s (admittedly rather sparse) audience in the Royal Welsh College’s Bute Theatre tell all their friends, and they tell their friends, and so forth into infinity, it could yet save the planet, and at last art will have justified itself after centuries of misguided, unmotivated aestheticism.

True, it isn’t always totally clear what is happening on the stage. In John Fulljames’s production (designer Tadasu Takamine), the guiding motif is the book, which might seem confusing in a drama about natural resources, until you realise that books use paper and people who read them eat food but produce nothing (the same could be said of people who go to operas, but we’ll let that pass). Clad in blotchy blue pyjamas, the seven angels land on a terrain covered with books arranged like dominoes, which all (or nearly all) tumble down neatly when pushed from one end. Later two of the angels (not the same two) don paper crowns and become a King and Queen – so often the fall guys in Sixties-style music theatre – whose son (the Prince, of course) gorges on books, tearing out pages and devouring them with a gay abandon that should have made Better World Books, who presumably supplied them, more than a little nervous. Later, the books he hasn’t masticated are rebuilt into a boardroom desk, a process which takes the duration of a longish interval. And in the end, of course, the whole caboodle is pulled apart and the books scattered around the stage, to become a Health and Safety hazard for the cast and conductor as they take their bow.

There is some feeling in all this that Maxwell has personally seldom read an opera libretto or attended a performance. When you read Seven Angels (in evil print), the text is strewn around the page like a Mallarmé poem, and the stage directions are as poetic as the text, as if, like the Pyramus play in A Midsummer Night’s Dream, the whole lot was meant to be set to music (an invitation Bedford happily declines). In my experience, poetic stage directions – “now it is as if the air itself is bursting to tell stories” – are usually a bad sign. They are a symptom of Worthy Opera. And Worthy Opera, alas, tends to precede humanity into oblivion.

Might this one be rescued by its music? Bedford is a gifted and highly accomplished young composer, but he is not, on this evidence, one who will take a text by the scruff of the neck and force it to tell us something we didn’t already know. His score for Seven Angels is just that: high-class background music, music that smoothly and efficiently supports the action, but rarely drives it. When it does occasionally take over, its debts are a shade too evident, though always paid with skilful, even beautiful scoring for a Britten-sized chamber orchestra dominated, however, by a quartet of violas, which lend the sonority a dark radiance that is perhaps the work’s most individual property.

As for the singers, they have to do difficult things without coming away with anything particularly shapely or memorable. Mostly it’s good, standard-issue modern arioso, excellent of its kind, as sung drama unremarkable. The performance, though, is superb. The work was commissioned by The Opera Group and the Birmingham Contemporary Music Group (who premiered it in Birmingham on 17 June), and between them they give the piece a chance it may or may not deserve.

I would single out Rhona McKail, as the angel-turned-waitress, a brilliant, focused high soprano, and the tenor angel-turned-Prince, Christopher Lemmings (pictured above), only because they have the biggest parts, ending up as Adam and Eve forever locked out of the Garden. But the whole cast, and the BCMG players under Nicholas Collon, are first-rate, and they all throw themselves into what is, after all, a difficult project without seeming to imagine that they might never be asked to do it again. That, at the very least, is a spirit that should help keep the planet alive.

• Seven Angels on tour until 16 July
• Find other performances by Birmingham Contemporary Music Group