Art, in one of the e-mails I have from him, he said:

Hi Jeri
I've been trying to figger out "what is folk misic" most of my life. I went to a private school that was very much into "folk music", and in 1946 started hanging around with the crew that gathered at Washington Square Park in NYC on sunday afternoons to sing and play. (I learned banjo and giutar - and have been a singer most of my life) I'm more into "solo" (Ballads etc.) but also into chanty's etc.