Probably the first "folk-singer" I heard, that was not family or a family friend, was Pete Seeger in concert at Bowdoin College in the late 1950's; I was probably dragged there kicking and screaming. He was good! Very energetic, got people singing along. My parents didn't think he had very much of a voice. My brother soon bought himself a banjo and then it was downhill for both of us ever since...