In Claude M. Simpson's great book "The British Broadside Ballad & its Music" (1966) there's a good bit of info about "The Freemason's Song", with the tune, which turns out to be in 6/4 time, fitting the rhythm "Come let us prepare, we brothers that are" - not the same as the bawdy Burns words, which would seem to ask for something in 4/4 time. All the same, one could straighten the tune out and make it fit, I suppose. Has anyone tracked down Bruce Olson's remarks?