"Pretty Saro" is an English folk ballad originating in the early 1700s. The song died out in England by the mid eighteenth century but was rediscovered in North America in the early 20th century where it had been preserved in the Appalachian Mountains through oral tradition. Cecil Sharp collected four versions in his American travels. It has been recorded by Judy Collins, Iris Dement, Pete Seeger, Doc Watson and others. I learned it from Pete Seeger's Bells of Rhymney book.