Elizabeth "Libba" Cotten, a self-taught blues and folk guitarist. As a child, she played the guitar upside down, since she was left-handed, requiring her to play the bass lines with her fingers and the melody with her thumb. By her early teens she was writing her own songs, including what would become her signature song, Freight Train.
As he mentions during her interview with Pete Seeger in another YouTube video from the same 1965 Rainbow Quest show, Cotten had stop playing her "ragtime" music due to her church's influence, and limited herself to the occasional church performance. However, she began public performances again after being "discovered" by the Seeger family while working for them as a housekeeper. As she notes in the interview, Cotten found the lost Peggy Seeger wandering through the aisles of a department store and crying for her mother. It was an opportune encounter. Cotten would eventually go to work for the Seegers, and picked up her guitar again.
Cotten's songs have been covered by the Grateful Dead, Taj Mahal, and Bob Dylan among others. Cotten was declared a National Heritage Fellow by the National Endowment for the Arts in 1984, and was recognized by the Smithsonian Institution as a "living treasure." She received a Grammy Award in 1985 when she was 90. Cotten passed away at age 92 in 1987.