This isn't meant to be a comprehensive list of social dancing in the Bay Area.
Irish Dancing
Irish set dancing Thursday nights in San Francisco. Lessons from 7:30pm to 9pm at the United Irish Cultural Center, dance at the Plough and Stars from 9:30pm to 11pm. Normally anywhere from 16 to 32 people.
Irish folk dancing Monday nights in Berkeley. Lessons from 7pm to 9pm, dance from 9pm to 11pm. Normally anywhere from 16 to 32 people.
Rotary Waltz and Other Victorian Dancing
Big mix of music, but mostly rotary and cross-step waltz, on 2nd Saturday nights in Oakland. Lessons from 7pm to 9pm, dance from 9pm to midnight. Normally anywhere from 30 to 60 people. I DJ and teach at this event sometimes, and was on the board.
Big mix of music, but mostly waltz, on Friday nights in Palo Alto. Lessons from 7pm to 9pm, dance from 9pm to midnight. Normally anywhere from 60 to 80 people.
The big fancy events are PEERS in Alameda and the often-dormant Gaskell Ball in Oakland.
Ballroom and Club Dancing
Big mix of music, depending on the night. I've come here exclusively for west coast swing. Lessons every day of the week, dances frequently in Danville. Normally anywhere from 20 to 100 people, depending on the event.
Big mix of music, dominant dance depends on the night. I come here for competition-style social ballroom. Lessons every day of the week, dances frequently in Oakland. I have particularly enjoyed classes with Karen and Michael. Normally anywhere from 8 to 100 people, depending on the event.