THE legacy of the Anglican philanthropist Thomas Coram is magnificent for two reasons. Shocked by the levels of child poverty in London, in 1739, he founded the Foundling Hospital for children who could not otherwise be cared for. And he secured the backing of George Frederick Handel, who wrote some of the world’s finest church music to raise funds for the cause.

Both of those feature in the revival of Helen Edmundson’s play Coram Boy, which is adapted from Jamila Gavin’s novel. It is a sprawling tale, whose plot the director Anna Ledwich only just manages to hold together. In the Ashbrook household, Young Alexander (Louisa Binder, who has a glorious voice) is a chorister whose heart is set on becoming a full-time musician, despite the opposition of his authoritarian father.

The family’s housekeeper, Mrs Lynch (Jo McInnes), is in league with Otis Gardener (Samuel Oatley) in a despicable scheme that takes advantage of desperate mothers. They part with their babies, assured that they have secured a place in Coram’s Hospital, but the children are murdered, and the money that has been given for their upkeep is stolen.

In Act Two, the life of the Ashbrook household’s abandoned, illegitimate son, Aaron (also Louisa Binder, but in a different wig, playing a different sex and a different ethnicity — there are some bizarre directorial choices), becomes intertwined with that of Toby, the orphaned son of a slave (Jewelle Hutchinson). There is an awful lot going on in the second half — too much, to be honest.

The production looks gorgeous. Simon Higlett’s two-level set hints at Georgian church architecture. The choral singing, under Stephen Higgins’s direction, is rapturous.

There are undeniably problems. The story is so hectic that at key moments it is unclear what is going on. There are confusing non-naturalistic scenes accompanied by awkward lightning flashes and salvoes of sound. And the adult cast, doubling roles and impersonating children, are not always convincing.

Enjoyed as a melodrama, however, this is a stirring production. Towards the end of a breakneck three hours, the audience is genuinely invested in the fate of the children whose lives are in the balance. The conclusion may not be entirely believable, but it is certainly affecting.

It is by accident that the play is being revived during an election campaign; but its two rallying cries are unexpectedly timely. A society must be judged by the way in which it treats its neediest children, and how we nurture the creation of music and art is indicative of the spiritual health of the nation.

Coram Boy continues at the Chichester Festival Theatre, Oaklands Park, Chichester, until 15 June, and then transfers to the Lowry Theatre, Pier 8, The Quays, Salford, until 29 June. Tickets from www.cft.org.uk (phone 01243 781312) and thelowry.com (phone 0161 876 2000).