Just tidying up a loose end! It transpires that what I remember as "Eireoidh me amaireach..." is the first verse of Cuachin Gleann Neifin, a title I either never knew or had long forgotten.

On translation: "cuachin" is literally "little cuckoo" - a term of endearment for a loved one, oddly enough. Gleann Neifin (various spelings) would be a placename.

Regards