Stephen Foster's music "Is part of every Americans culture," wrote composer Virgil Thomson, and certainly this is true, for few American composers have created songs as lastingly popular as "Beautiful Dreamer," "Oh Susanna," "Jeanie with the Light Brown Hair," "Swanee River" (properly "Old Folks at Home"), "Camptown Races," and "My Old Kentucky Home, Good Night." The fact remains, however, that Foster's melodies have suffered continually at the...