And Joni Mitchell was not an "unknown singer" in Canada by Summer 1967. She appeared on the very popular CBC national show, Take 30, in May (and many others already knew her from appearances as Joni Anderson on CTV back in 1965.)

https://www.youtube.com/watch?v=UR86OFB4EiA

Perhaps not a household name and far from the level of fame would she would achieve in a few short years, but not unknown.