Sadams at bistream.net (27th August 2004) is probably right about the "Zeitgeist". Possibly 2 or 3 years ago I posted asking for the words of "The Old Oak Tree" to the tune sung by Robin Morton of "Boys of the Lough" (only some of which I could remember) but no-one was able to help me then (in this version it is Squire McCollum, which is rather close to the Squire McCallian in the NFLD version by Malcolm Douglas posted by "Q" on 28th July 2004 or the Squire McCullough version posted by Joe Offer on 29th July 2004). All these names beginning with Mc are perhaps especially associated with Northern Ireland, though whether (as Robin Morton says in the sleeve notes to the Boys of the Lough 1st album on which this song appears) "Whether this song relates to an actual murder I do not know." However it is a good song (murder ballads usually are, eg Tom Dooley, Poor Ellen Smith, Omie Wise, etc)and I particularly like the last verse on the BOTL version (after Squire McCollum, overcome with remorse, shoots himself):

And they buried him just where he lay
No Christian grave got he
For no-one was found to bless the ground
Beneath the old oak tree

Despite its melancholy sound I don't think it is in a minor key.