Not counting songs sung at school or heard on the radio, I can pin down my first encounter with live, untamed folk song to a precise date; Christmas eve 1966 when I came across a wild & well oiled bunch belting out mostly Irish stuff in the Exchange pub in Harrogate. This disreputable establishment is now now long gone. Even a 'genteel' spot like Harrogate had its share of rough pubs.
The song that sticks in my mind was "Leaving of Liverpool" which was the first song I learned to perform in public a year or so later.