The centrepiece of this outstanding disc of choral works by Harrison Birtwistle, all recorded for the first time, is one of the beautiful and most intensely personal of his recent scores. The Moth Requiem was first performed in 2012, and brought to the UK at last summer's Proms. Its core is a setting for 12 female voices with an ensemble of alto flute and three harps, of a poem by Robin Blazer, librettist of Birtwistle's opera The Last Supper. The text takes a description of a moth trapped inside the lid of a piano at night as the starting point for a meditation on transience and loss; around it the singers sing the scientific names of a dozen species of British moth, some of them common, others teetering on the brink of extinction. The instruments weave in and out of the voices, sometimes evoking the noise of the insect bumping against the piano and its strings, sometimes taking off on flights of their own; the sound world is fragile and exquisite, the music spare and elegiac.
The other major works included here are connected to two of Birtwistle's operas. Composed in 2004 on a specially written text by David Harsent, The Ring Dance of the Nazarene is a pendant to The Last Supper. The Nazarene of the title is Christ, alternately represented by the solo baritone (the superb Roderick Williams here) and the chorus, and the event it depicts is reported in one of the apocryphal gospels; an Iranian drum, a darbuka, represents the dance that Christ enacts before his disciples. On the Sheer Threshold of the Night, from 1980, is one of the by-products of Birtwistle's work on his stage masterpiece The Mask of Orpheus, a setting of an early Christian poem about the Orpheus myth by Boethius that generates a miniaturised drama of its own. It's an important, scrupulously presented collection.