Nolwenn - Tri Martolod [Breton music]
This is a traditional Breton song. Breton is a dialect that is—or rather used to be—spoken in Brittany, a Northwestern region of France. Related to Welsh and Gaelic, Breton (Brezhoneg) is a Celtic language, hence as a French-speaker, I can't understand a word of it. However the lyrics have been translated on the website here (Thanks to purplelunacy and clinke).
A very nice-sounding tune, isn't it?