Elizabeth "Libba" Cotten (1893–1987) was an American blues and folk musician, singer, and songwriter. A self-taught left-handed guitarist, Cotten developed her own original style. She played a guitar strung for a right-handed player, but played it upside down, as she was left-handed. This position meant that she would play the bass lines with her fingers and the melody with her thumb. Her signature alternating bass style has become known as "Cotten picking". 

 

By the age of 8 she was playing songs. By her early teens, she was writing her own songs, one of which, "Freight Train", became one of her most recognized. She wrote the song in remembrance of a nearby train that she could hear from her childhood home. She married at age 17 and soon after gave up playing the guitar for 25 years, except for occasional church performances. She did not begin performing publicly and recording until she was in her 60s. She was discovered by the folk-singing Seeger family while she was working for them as a housekeeper. In the later half of the 1950s, Mike Seeger began making bedroom reel-to-reel recordings of Cotten's songs in her house. These recordings later became the album “Folksongs and Instrumentals with Guitar”, which was released by Folkways Records. In the early 1960s, Cotten went on to play concerts with some of the big names in the burgeoning folk revival. Using profits from her touring, record releases and awards given to her for her own contributions to the folk arts, Cotten was able to move with her daughter and grandchildren from Washington, D.C., and buy a house in Syracuse, New York. She was also able to continue touring and releasing records well into her 80s. 

https://en.wikipedia.org/wiki/Elizabeth_Cotten