Sisters Rachel and Becky Unthanks are revered for their crystalline chamber-folk and dazzling vocal interplay. This is a fascinating exploration of the work of two avant-garde pop composers, all the more intriguing for delivering male concerns from a female perspective. Rachel’s husband, pianist and producer Adrian McNally, provides a majestic, cinematic backdrop for these soaring explorations. Both Antony’s transgender post-politics and Robert Wyatt’s caged revolutionary semiotics receive deservedly reverent, illuminating treatment from two wondrously entwined womanly voices.