In anticipation of their 25th anniversary (in 2005) the Vasari Singers commissioned pieces from 10 composers, among them Francis Pott, who produced a setting of Psalm 23. This consoling, meditative piece – conceived as a section of an extended anthem – subsequently developed into this oratorio which lasts an hour and a half. A clear indication of its themes for reconciliation and tolerance in a violent world and a condemnation of extremism can be found in the score’s inscription “To the memory of Margaret Hassan and all innocent lives lost in Iraq or beyond”. Potts combines Biblical texts (from the Four Horsemen of the Apocalypse to the Psalms) with William Blake and war poetry. One of the most chilling sections culminates in a repeated chant of the line “The dead are all on the same side”, a translation from the French Great War poet René Arcos.

The Cloud of Unknowing is painted on a large canvas and there are times when the material seems over-stretched. The quicker, more dramatic choral music lingers longest in the mind. The choir’s interaction with the organ reminded me at times of Francis Jackson’s splendid (but largely overlooked) “dramas with music” Daniel in Babylon and A Time of Fire. Jeremy Filsell’s flawless playing draws numberless nuances from Tonbridge School’s Marcussen instrument.

James Gilchrist is a passionate and occasionally volatile soloist; an irritating bleat creeps in when he really pushes the volume. Jeremy Backhouse and the mighty Vasaris give this uneven piece everything they can muster. It is worth persevering with.