I ALWAYS have to suppress a groan when a concert opens with a pious speech by an Amnesty International bigwig, followed by the portentous lighting of a candle which is left to flicker symbolically in front of the stage. So it says much for Richard Blackford’s Voices of Exile that my sardonic mood was dispelled well before the end of this hour-long oratorio.

Premiered three years ago, but newly reworked with full orchestral accompaniment, it’s a sincere, well-calculated work: a kind of extended protest song against the manifold persecutions that turn innocent victims into refugees, and refugees into innocent victims. Blackford draws his texts largely from poems, songs and testaments of exiled writers from many different countries and eras — often heard via tapes of the exiles themselves. He then weaves a lush cocoon of very English choral polyphony round these haunting foreign voices, rather as David Fanshawe did 30 years ago in his African Sanctus.

At its best, as when a recording of a beautifully inflected Macedonian folksong is counterpointed with its own translation and then against a live choral backing, the technique is evocative and touching.

But Blackford sets other texts to original music of his own. And here the work falters slightly. His orchestrations are resourceful, his tonal harmonies old-fashioned but strong, his use of classic forms such as fugue and passacaglia apt, and his word-setting intelligent — yet the piece lacks the stamp of memorability or the ability to startle. It’s like a good film-score: impeccably crafted, but too politely subservient to a non-musical objective — in this case, the human rights movement.

Still, this is an eminently singable, thought-provoking choral work that deserves wide circulation. Good to hear, then, that the performers who gave it such a polished interpretation under David Hill’s exuberant direction — the Bach Choir, New London Children’s Choir, Philharmonia Orchestra and soloists Catherine Wyn-Rogers, Gregory Kunde and Gerald Finlay — are recording it for Quartz.

Boosted by battalions of extra brass, the choir and orchestra then gave a tremendously punchy account of Walton’s Belshazzar’s Feast. Indeed, Hill hurled his forces through the last chorus at such a lick that I feared the whole thing would end in a spectacular accident. So it did. About 20 bars from the end, the conductor’s baton flew from his hand, pirouetted dangerously over the first fiddles, and then plunged into the stalls. Great stuff. Bach Choir concerts haven’t been this frisky for decades.