Joe, I used to think that a song should be over a hundred years old, but some examples have led me to change my mind. I don't think a lot of the songs in Laws 'American Balladry from British Broadsides' (all in DT) were that are old when collected.One example: Look at "Marching to Fenario" in Sharp-Karples and some other collections. The Scots "Bonnie Lass of Fyvie, O" is a version of the song (It's rewritten from an Irish ballad "Pretty Peggy of Derby, O", c 1780, but uses the original Irish tune). The rewritten American version was never sung to that tune. The American version is from 'Pretty Peggy and other Ballads', Oliver Ditson, 1880, where it had a new tune. [Ed Cray discovered this from a copy at Harvard. There's another copy at the Library of Congress.] Most of the American versions (fell in love with a lady like a dove) were less than 50 years old when collected. Should they be called traditional songs?