Yes, Felipa. I meant "Petrie." Thanks for the correction.

Drummond believes that "The Young Man's Dream" and "The Groves of Blarney" were unlikely to evolve into the Ross-Petrie "Air" between 1834, when Petrie collected in the area, and the early 50s, when Ross sent it to him - shortly after overhearing it for the first time. That's why he brings Ritter into the equation.

Ritter's influence is plausible but unnecessary, because the source of the "variant" might well have been the fiddler/violinist that Ross heard play it. (Ross felt no need to inquire.) Surely, though, if it had been much older or long in tradition or widely known even in the area, Petrie would have found other versions.

Whenever it may have emerged from improvisation or was more deliberately tweaked into existence, the number of people on earth in 1853-1854 familiar with what much later was known as the "Londonderry Air" might have been countable on just a few fingers.