I learned this Scottish/Gaelic song in Goldenbridge. I was in Sr. Fabian’s choir. She came from Donegal, so she would have been very much in touch with Scottish music when she was growing up. Sr. F. was a fluent Irish speaker. Whenever nuns from Carysfort College came into the classroom, she always reverted to speaking in Irish. One immediately got the impression that the pair were in discussion about one, whenever their eyes happened to gaze upon one at the time of their As Gaeilge tête-à-tête.
That sort of thing also frequently happened to me in Switzerland, when the head of the household spoke in French at the dining table when she discovered that I was picking up on the Swiss-German language.
The song is very haunting. Nana Mouskouri is very versatile in many languages. I think musical people, per se, find it very easy to sing in foreign languages.