Marie-Josèphe Bertrand (1886-1970), born Martay, known as “ Madame Bertrand ” and nicknamed Joze Ar c'hoad in Breton – literally: “Josée of the woods”, was a Breton singer who influenced many contemporary artists.

Born in Plounévez-Quintin, she grew up in a poor family of agricultural day laborers where singing held a central place. Daughter of singers, she acquired the style and repertoire of her parents consisting of songs to listen to, dance to, and march. She performed publicly from the age of 12 at wakes, fairs, weddings, sometimes accompanied by her father or sisters.

In 1902, at the age of 15, she married a clog maker from Saint-Nicolas-du-Pélem, Vincent Bertrand (alias Mathurin or Matao) and gave birth to the first of their six children at the age of 17. They lived in a hut ( lochenn ) with very basic comfort in the middle of a beech forest, hence her nickname "Josée du bois", and changed locations according to the construction sites. Marie-Josèphe then learned about medicinal plants and exercised her talents as a healer.

In 1919, with her husband who had returned from the war, they settled in Canihuel as clog makers. In 1924, Madame Bertrand opened a café. She sang whenever she felt like it and sometimes to liven up gatherings. When the first "modern" fest-noz were organized, her son Guillaume took her to participate in competitions where she won prizes.

His repertoire was collected by Claudine Mazéas between 1959 and 1965, among which his interpretation of the gwerz of Skolvan will remain famous.

She died in 1970 at the age of 84.

Many Breton musicians consider her an exceptional singer and her performances are a source of inspiration for many of them. Various records and publications, notably edited and published by Dastum, are dedicated to her.