In the late 60s and early 70s what I never came across was participatory events such as instrumental sessions or singarounds. Even our local singers club operated fairly formally as an open stage event. It may be that they were just absent in my area or, in pre internet days, you just had to know the right people. These days there still seems to be as much opportunity to participate but it is less inviting to the outsider as fewer events are designed for performing to an audience.