I've been singing Pat Murphy as long as I have Mary Mac. In fact I stole this Mary Mac, Bonny Black Hare, and Pat Murphy all from the same tape. I bought it from a street singer, Steve Lauterbach, at a Rennaissance Fair in Colorado in 1987.

As a folk process note, I usually sing the last line of the first verse as:

And O'Leary came with bagpipes and music for to play

Instead of:

And a lady came with bagpipes and music for to play