On February 13, 1883, Richard Wagner died of a heart attack in Venice. Jonathan Harvey’s Wagner Dream imagines that in the composer’s final delirium, he was visited by a Buddhist spiritual guide and granted a vision of Die Sieger – the Buddhist opera which he planned but never wrote.

Given Harvey’s own Buddhist beliefs, and his untimely death last year, the idea is both powerful and poignant; and this belated UK premiere by Welsh National Opera was commendable and brave.

In Pierre Audi’s production, two worlds coexist on the stage – simply represented by a split-level set. The Wagner household is presented in monochrome, and with spoken dialogue. Behind them (and the onstage orchestra, conducted with pinpoint accuracy by Nicholas Collon) is the glowing red-and-ochre world of ancient India, where Die Sieger is played out in music of breathtaking beauty.

And while the German-speaking actors seemed inhibited, the singers were wholly committed: Claire Booth’s impassioned Pakati gave the story its soul, while David Stout as the Buddha fittingly dominated every scene in which he appeared.

Richard Wiegold, as the spirit-guide Vairochana, had some of the score’s loveliest music, delivered with a heart-melting simplicity.

And yet – for this listener, anyway – Wagner Dream is problematic. Its central narrative of renunciation may well convey a profound truth to a convinced Buddhist. To this worldly westerner it felt, at root, cold – something that could never be said of Wagner’s work.