I can't pin it down for you I am afraid, but Mouez Breiz (Voice of Brittany) was a record label operating out of Quimper in Brittany from 1952 to the 70s. Presumably this is a sound file of a record of theirs, though I can't find it in their discography. 'Noce Bretonne' means 'Breton wedding' of course, and Plouray is a commune in the south of Brittany, just on the boundary between the departments of Cotes d'Armor and Morbihan. Lots of traditional music and singing round there, including the famous kan ha diskan - mouth music for dancing. Manu Kerjean was born nearby and lived in Plouray, and the Goadec sisters are from up the road.