June Tabor and Maddy Prior were in very different places professionally when they made this duo album in 1976. Tabor was in the early stages of establishing herself as a solo artist, while Maddy Prior had been the lead singer for Steeleye Span for six years and would continue to be a darling of the British folk and folk-rock scene. On Silly Sisters, Prior’s ethereal soprano voice blends astringently with Tabor’s darker alto, and they deliver powerful renditions of such traditional fare as “Burning of Auchindoon” and “The Seven Joys of Mary,” with minimal accompaniment.