Hannah Kendall’s hour-long first opera is a chamber-sized piece with just one principal, an atmospheric off-stage female chorus of three (members of the Juice Vocal Ensemble) and a skilful four-piece instrumental group, consisting of string trio plus harp, efficiently conducted by Rebecca Miller. Kendall and her librettist Tessa McWatt share a Guyanese background with their subject.

The poet and activist Martin Carter was among those who struggled for what was then British Guiana to become an independent state – which eventually happened in 1966. Drawing on his life and poetry, The Knife of Dawn shows us Carter in one of his two periods in prison in the early 50s for his political involvement.

Designer Martin Thomas’s simple prison cell and John Walton’s straightforward staging cannot give the piece a momentum that it inherently lacks; in some ways the result feels closer to a staged song-cycle than a drama. But the intensity of Carter’s passionate engagement both with his country and his art comes over with dignity and eloquence in baritone Eric Greene’s performance, which is a genuine tour de force of empowered vocalism and expressive concentration.

Kendall gives him plenty of opportunities, and there’s a wide variety of mood and musical gesture on display, leading up to Carter’s final insistence that he is, fundamentally, a poet rather than a politician. Often ingenious in its sharp definition, the instrumental accompaniment adds texture and colour as it supports Greene’s heroic vocal line.