At risk of looking like a complete idiot--which has never stopped me before--would one of the Irish Gaelic speakers/readers please check to see if that's "The Rising of the Moon" in Gaelic? (It seems to kind of match the lyrics and scansion posted by GUEST on 09 Sep 11 - 06:48 PM.)

http://corpas.ria.ie/index.php?fsg_function=3&fsg_id=4720