I've been told by a renowned authority on Scottish ballads that the song originated in Aberdeenshire, North East Scotland and 'Shule aroon' used to be 'Folla Rule' - an ancient hamlet near Fyvie (mentioned in 'The Bonnie Lass o Fyvie' which Dylan amonf others covered). The lyrics changed after the song was taken overseas with emigrants to the New World. Just an addition to the debate!