in An t-Amhrán Macarónach, O Muirthile has "ar chnocainín ...", "on the hillock...." so the "h" is added to indicate aspiration or lenition after the preposition "ar"; but that is a line in the song, not the title of the song.

O Muirthile righted the spelling from the ballad sheet, it is hard to make head or tail of the likes of "eir chuukapeon crach Chilvurra"!