But I'm confused by the conflation of 'The Unquiet Grave ' and 'The Twa Brithers'.
There are a number of versions of this ballad where the death is accidental and the lover of the dead brother comes along and sings/charms him out of his grave.
My point wasn't about a deliberate process but an accidental one in which versions of one song move closer to another. 'Lord Bateman' isn't the same as Harry Cox's 'Turkish Lady' but they're very close relations. Maybe there's a third song which contains both of the aforementioned?
Dick, I was thinking of larger themes than common floating verses. Leaning one's back against an oak doesn't make 'The Cruel Mother' a version of 'Waly,Waly' but 'The Maid and the Palmer' seems to have lent the 'Cruel Mother' a set of undeserved punishments. Or are they actually different. Sorry, I think I'm repeating my original point.
Paul