The first two lines "Cummer go ye before, cummer go ye/Gif ye will not go before, cummer let me" do come from the trial records. The rest was obviously made up in the twentieth century - I assumed Davidson did it, but Murray refers to a source of ten years earlier. I'll see if I can look that up.

There is a tune for the authentic couplet, given with no source in the notebooks of Lady John Scott. It's nothing like Lowe's tune and badly garbled (Scott's copyist was dreadful). I completed it with a couple of bars that seemed right to me and included it in my "Embro, Embro" CD-ROM. Scott was no scholar and there's no evidence that her tune really goes back to James VI's time.