Isla Cameron was one of a quartet of key figures in England's postwar folk song revival -- and to give a measure of her importance, the other three were Ewan MacColl, A.L. Lloyd, and Alan Lomax. Her public singing career began quite by accident; she was a member of a theater workshop run by Joan Littlewood, who was then the wife of Ewan MacColl (1915-1989), when she and MacColl met backstage. They began a long friendship and professional relationship, and MacColl helped secure Cameron's first recording, an unusual unaccompanied performance of "The Fair Flower of Northumberland...