Interviewed before the first UK performance of The Moth Requiem, given in this BBC Singers concert under Nicholas Kok as part of the Proms Chamber Music series, Harrison Birtwistle recalled how as a young man he was fascinated by natural history in general and moths in particular – an interest he returned to in this 20-minute choral work premiered last year in Amsterdam. Scored for 12 female singers, three harps and alto flute – a combination resulting in an entirely characteristic colouristic scheme – it sets a poem by Robin Blaser, the librettist of Birtwistle's opera The Last Supper, who died in 2009, alongside the Latin names of a dozen varieties of moth, all now extinct.
The disappearance of living things underlies the elegiac feel of the work, though, as Birtwistle suggested, there is anger in it, too. Blaser's text – The Moth Poem – recalls that the location of the source of a mysterious sound in his home was a moth trapped inside a piano. Strange and subtle effects from the accompanying instruments – played here by Lucy Wakeford, Helen Tunstall and Hugh Webb, alongside flautist Philippa Davies – give the result an enriched atmosphere, with the words dissolving in cloudy textures punctured by sudden, percussive stabs. The result is a fascinating addition to Birtwistle's oeuvre.
Here, it was preceded by the third group of Gustav Holst's lively and luminous Choral Hymns from the Rig Veda, imaginative settings translated by the composer from Sanskrit and delivered here with translucent accuracy, Wakeford once again underpinning an all-female ensemble. The central unaccompanied group consisted of two items from the Eton Choirbook – William Cornysh's Ave Maria, Mater Dei and Walter Lambe's Stella Caeli – plus Imogen Holst's Hallo, my fancy, whither wilt thou go? – a setting of the 17th-century Scottish poet William Cleland. The Holst piece struggled to hold together such a diffuse text, while the pre-Reformation items could have done with the effortless sense of style the group revealed elsewhere.
* Watch the concert here, available until 19 August.