You got me blushing again!! Now for the tune, well the person I stole the tune from was Woody Guthrie who sang I Ain't Got No Home on his Dust Bowl Ballads. He in turn stole it from the gospel group the Carter Family. Their song was called I Can't Feel At Home In This World Anymore, or something like it. That's as much of the tune's history that I know, though I wouldn't doubt it if they had stolen it from some other song. Common practise.