Varied & various venues from my vile and vicked youth:
Leon's Coffee House, in an icecream shop basement in N Plainfield NJ.
[ I have met people all over the country who actually went there, ca1964 ! ]
The Id & Ego in Milwaukee. Cafe Pergolese on Chicago's Northside.
Ethical Culture Soc basement in Rittenhouse Sq Phila.
I'm now a "user" at Coffee Catz in Sebastopol CA - great open mic !