UPDATE: A listener over on Melodeon.net supplied the following information "Lady Cassilis' Lilt" is a very old tune (she died in 1642) and was used for the ballad Johnny Faa and the Earl of Cassillis' Lady, the origin of Gypsy Davy/Gypsy Laddie/Gypsy Rover. It's most commonly heard nowadays as the tune for the Jacobite song "Wae's Me for Prince Chairlie."