The Unthanks see the humour in their reputation for bleak music: following comic accordionist Tim Dalling, pianist Adrian McNally deadpanned: “Right, you’ve had your fun. We know what you really came for.”

Becky and Rachel Unthank’s unique singing voices conveyed sorrow, wistfulness and stony-hearted rage, and they added elaborate backbeats by clog dancing.

They were backed by a string quartet, double bass and soaring trumpet, with drums producing rolling waves of thunder to add to the uneasy atmosphere.

Magpie was a compellingly sinister reworking of the traditional counting rhyme over the drone of a squeezebox.

A short ditty sourced in Cecil Sharp House developed into Mount the Air - a hypnotic, slow-building 10-minute beast of a song, offset with trumpeter Victoria Rule’s restrained additions inspired by Miles Davis’ Sketches of Spain.

The band were at their best picking out the subtly disturbing, as in Last Lullaby: based on Golden Slumbers, it took a darker, more final tone of farewell inspired by collections from the Foundling Museum.

Violinist Niopha Keegan added her voice to the sisters’ unaccompanied slow harmony on chilling Yorkshire song The Wind, The Rain, and the show concluded with a stirring cover of King Crimson’s Starless.