I doubt whether anything the year brings for Birtwistle’s 80th birthday is going to dim the lustre of this excellent recording of his choral music. Nor surpass it in importance, perhaps – it seems to me we may have failed to realise how close these pieces are to the core of him, in no way apart from the thrust of what he does on other stages, orchestral and instrumental, lyrical and theatrical. The more you explore the collection, the more aware you are of his fingerprints and the concerns we have come to think of as characteristic – to do with memory and memorialising, with transience and loss, call and response, myth and ritual, and with retellings of old stories in striking new ways. And as with other prime movers and shakers, he is his own man, whose sound and voice we immediately catch, recognisable from any two notes he puts together.

There are instruments here as well as voices – woodwind, harps and percussion rather than bowed strings, and sometimes only one, as in Carmen Paschale, the earliest of these pieces, from 1965. There it is a flautist who electrifies the setting of an Easter poem (from Helen Waddell’s Medieval Latin Lyrics) at the mention of a nightingale. In The Ring Dance of the Nazarene (2003) there are woodwinds as well as a baritone soloist with the choir, together with a big part for a drummer on the Iranian darabuka, performing a kind of percussion continuo and symbolising perhaps ‘the Nazarene’ (= Christ) as dancer. He is given a dramatic entry. David Harsent, several times Birtwistle’s librettist and one of his preferred collaborators, did the text specially for the piece.

Long ago the church decreed against the role of dance in worship, and indeed there’s nothing on the CD that the Christian liturgy could find room for, with the exception of the short Lullaby composed for the trebles of Southwark Cathedral. And yet – as John Fallas points out in the booklet-note – in Birtwistle’s inspired craftings and treatments we are rarely far from the themes of Western sacred music: Christ’s life, death and, for believers, his continuing life in us, together with the genres that are part of our memory: hymns, motets, a requiem of sorts.

This one, The Moth Requiem, the most recent of the six works (2012), revisits the theme of loss and is at once a meditation on loss and a memorialising of what is lost. Moths? Well, yes: the poem by Robin Blaser which prompted it was itself brought into being by his efforts to trace mysterious sounds heard in his house at night; their source was discovered to be a moth caught inside the lid of his piano. Do not expect any reminiscence of a traditional Requiem Mass but rather, through the incantation of the Latin names of moth species, some believed to be nearly extinct, a commemoration of departed loved ones. It is an extraordinary leap of imagination to reach the achievement here from that starting point. But no one could fail to catch the quality of the composition as one of the most personal of Birtwistle’s recent scores. Terrific stuff, with already the feel of a classic, and admirably served by the BBC Singers plus alto flute and three harps, and the conductor Nicholas Kok. May I ask for the departed John Alldis and his choir to be remembered? I expect he’s already in here somewhere. Without the work he did and the standards he set in the 1960s there would be no BBC Singers as we celebrate them today.