The Human Comedy, Young Vic, London

The Young Vic has an admirable tradition of kicking off its year with a production that pulls in the local community to play alongside professionals in the role of chorus – and the venue has had some of its most signal recent successes in this department. It now launches its 40th anniversary season in joyous fashion with the belated British premiere of The Human Comedy. A flawed, affecting show by Hair composer, Galt MacDermot, this piece flopped on Broadway in 1984, but it fits the bill here to an almost parodic degree in its celebration of the healing power of community and the unifying nature of song.

The imaginary Californian town of Ithaca is the main character in this through-sung pop opera, set in the Second World War and based on William Saroyan's 1943 novella. It would be easy to scoff at the idealised picture the show paints of a place where a gun-wielding thief can be disarmed by compassion and where the poor consider it their privilege to give alms. But the mood is darkened by the repeated, ominous tapping of the telegraph machine as it receives notification from the War Office of the death of loved ones and by the troubled coming-of-age of Homer (a splendidly poignant Jos Slovick), the young telegram messenger whose older brother is out at the front.

MacDermot pays tribute to the spirit of the townsfolk with a score that sounds like a hymn to the eclectic wealth of US popular music. Rapturously sung here to the accompaniment of a dynamic band, it slips between swing, blues, gospel, folk, the hymn-book and jazz. John Fulljames's warm, rousing production – sparely staged with wooden-crate terraces for the scalp-tingling chorus – movingly draws out the underlying melancholy. Playing Homer's widowed mother, Helen Hobson sings with an un-maternal aggressive edge as though her stoic wisdom has been wrested from near-despair.

To 18 September (020 7922 2922)