Just a brief explanation of my odd posting above. I wrote the first sentence, listened to the song, and then wrote the rest. Thus I can confirm that Barzaz does NOT perform it as an instrumental, but as a song sung by their vocalist, Yann Fanch Kemener. If you want to hear the song sung, it's a very good CD.

YFK also has a songbook out, which I do not own. It's possible the song in question is in the book.