Jerry Garcia idolized guitar virtuoso Elizabeth Cotten (1893-1987). She wrote the song "Freight Train" when she was in her early teens. A left-hander, she simply flipped over her guitar without restringing it.
After marrying at age 17, she gave up guitar playing for 25 years. When she was in her 60s, she got a job housekeeping for Pete Seeger's family, who discovered they had a genius in their midst, and soon she was touring and recording to worldwide acclaim.
In the video below, Cotten describes her two-finger "Cotten Pickin'" style before performing "Freight Train."