Elizabeth “Libba” Cotten 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 required her to play the bass lines with her fingers and the melody with her thumb. Her signature alternating bass style has become known as “Cotten picking.”
–from Wikipedia: https://en.wikipedia.org/wiki/Elizabeth_Cotten
For More Information:
“She was a maid at 9, wrote a hit song at 11 — and won a Grammy at 93”
by Nina Renata Aron
North Carolina Highway Marker for Elizabeth Cotten