Connect with The New York Pinewoods Folk Music Society (check out their website). It has one of the best listings anywhere for folk music in the city-- you will be astounded at the listings!

They will mail you a free sample newsletter, and I suggest you join the group (special rate for out of towners) so you can attend one of their free to members concerts.

You'll have a great time,there's not a day that goes by in NYC where you can't hear folk music somewhere.