The Wainwright Sisters are in fact half-sisters, two women with the same father and different mothers, though the three parents involved are all important figures in contemporary folk music, and the sisters themselves were gifted performers of note before they began working together. The Wainwright Sisters are Martha Wainwright and Lucy Wainwright Roche; Martha's parents are singer and songwriter Loudon Wainwright III and Kate McGarrigle, who performed with her sister as Kate & Anna McGarrigle, while Lucy is the daughter of Wainwright and Suzzy Roche of the vocal group the Roc...