The first time I saw Joni Anderson (later Mitchell) was at the 1964 Mariposa Folk Festival with David Rea. It was held in Maple Leaf Stadium.
I believe I saw Bonnie Dobson in Orillia at one of the first Mariposas. I didn't see either of them in Hamilton.
I did see Al Cromwell, Jackie Washington, The Greenbriar Boys, Josh White Jr. and a bunch of other folks at Hamilton clubs.