Mary Barthelemy (1947) is originally from Minnesota. She grew up in a creative home, with parents who appreciated international folk music and dance. The family moved several times, from Minnesota to Texas, to Massachusetts and back to Minnesota. In new environments, the family found social involvement thru international folkdancing. Mary got tricked onto the dance floor as a teenager and got into the groove of kolos, the hambo and contras etc. Playing music for dancing, on cornet and folk flutes, turned out to be fun too.
While studying at University of Chicago and University of Minnesota (anthropology and ethnomusicology, 1966-1973) she was active in Balkan, Scandinvian and international folk dance groups –both as musician and dancer. She was also active at Folklore Village Farm, Wisconsin, during this period.

Traditional music and dance became a priority for her in exploring the world, seeking niches in which to participate and learn. In the 1960s, dance workshops with Gordon Tracie of Seattle - and the fiddle music he presented - triggered extra curiosity for Scandinavian traditions. This eventually led to an open-ended journey to Scandinavia in 1974. The following 8 years were spent with periods of work, study and travel in rural Norway (Heidal, Oppdal, Rauland) and the US (Minneapolis and Folklore Village Farm).

Since autumn 1982, Mary has been based in the Røros area of eastern Norway. She is married to traditional musician Olav Nyhus, and works as a free-lance guide for the Røros Museum and the local tourist office. The historical town of Røros is on UNESCO's World Heritage List and attracts visitors year-round. Over the years, Mary has participated in many phases of folk music and dance sharing. She has taught workshops, participated in festivals and concerts, and played for dances. She has also participated in recordings, mostly playing wooden flute/recorder: 2 with Hans Brimi and Jon Faukstad, and more than 10 with ”Dalakopa”. On fiddle, she has taken part in 4 recordings with a local fiddle group "Glåmos spelmannslag". In 1997 Mary began exploring into the history and identity of the legendary Norwegian Gypsy/Traveler fiddler called ”Fant-Karl”/”Karl-Fant”. This has resulted in a Masters thesis (Rauland 2006), a book (Rørosmuseet 2007) and CD anthology (Ta:lik 2009), and leads constantly to new involvements both in and outside of Norway.