Wow, I just found this site and this thread looking for info on the Drinking Gourd. I arrived in SF in April 1963 and at some point started going to the Drinking Gourd pretty regularly. Great folk music and cheap food and beer/wine. I definitely remember Jean Ball, and also the group Town Criers that included a large bass instrument. Marty Balin would sometimes appear for their second (late) set and really wail in great counterpoint to the group's folk harmonizing.