Thompson, thanks for The Irish Times article paste. It has lots of good information but also states as fact some notions that are really circumstantial conjecture, such as that the original Irish was "Cailín ó chois tSiúire mé". It may have been, but this cannot be proven, and the manuscript Murphy uses to suggest this is a century after the English broadside. Was it the title/chorus that passed into Scottish Gaelic? Again, conjecture, as the waulking song is (I think) late 19th century, and lots of songs use the same phrases and have the same titles but are unrelated, as with songs called As I walked out, or The Croppy Boy, or The Unconstant Lover, etc. etc.

leenia, the Callino in the Fitzwilliam Virginal Book is variations by William Byrd. It was common for lute, cittern and keyboard composers to write variations on broadside melodies.