‘There is one work … that reassures me that I have the right to compose’, wrote Francis Poulenc about Figure humaine, his a cappella cantata on eight poems by Paul Éluard. Composed, in secret, during some of the darkest days of France’s occupation by the Nazis, this stirring masterpiece of the 20th-century choral repertoire is performed far too rarely: its combination of remarkable difficulty (textual as well as musical) with relative brevity (lasting only about 20 minutes) poses a programming conundrum.

Enter the chamber choir Skylark, who have now recorded the inspired solution they began presenting in performance in 2017. Founded in 2011 by artistic director Matthew Guard and doubly based in Atlanta and Boston, Skylark have become known for Guard’s artful and thoughtfully researched programming as well as for the exquisite balance and expressive warmth with which it is realised by the ensemble.

The concept of interweaving the eight movements of Figure humaine with songs and hymns associated with the American Civil War occurred to Guard as a practical way to make Poulenc’s cantata more accessible to Skylark’s audiences – and to create a stand-alone programme that adds another layer to the themes of resistance and resilience defying the darkness of war.

Poulenc wrote Figure humaine over the summer of 1943, outside Paris, to surrealist poems Éluard had circulated while working in the French underground. Éluard’s images of the angst and oppression of war prompted Poulenc to compose an astonishing array of textures and contrasts for 12-part antiphonal choir – including a menacing fugue in the seventh movement that, notes Guard, seems to depict the choir ‘being pulled into the underworld’ before the piece’s ‘first glimmer of true hope’ at last emerges in the climactic final movement, ‘Liberté’ (leaflets of which text were famously dropped by the RAF over French occupied territory).

Guard interpolates eight Civil War-era songs, ranging from the devastating but little heard ‘Break it gently to my mother’ to the universally known ‘Battle Hymn of the Republic’ (an old American camp meeting tune set to Julia Ward Howe’s stirring lyrics). A priority was to select songs ‘that would make sense musically and textually in the context of Poulenc’s work’. The songs have been impressively arranged for a cappella choir – five of them by Guard himself – to overlay dramatic effects and textural variation on top of the ballad-like repetition and static harmonies of the original tunes.

The singing here is a model of lucid intonation, subtle dynamic control and dramatic presence, with an unwavering focus on the meaning of the texts. Though the splintering of Poulenc’s work may be a problem for some (one easily resolved in digital format), the interpolation of songs about the effects of war from another era expands the tragic sense of relevance – and intensifies the joyful, liberating surprise of the sopranos’ E above the treble stave at the end of Figure humaine, where Poulenc’s vocal leap of faith resounds with the shock of hope.