The Web site has the monthly schedule of groups. Johnny Foley's This very pleasant pub near Union Square is building a new music room, and hopes to attract major Irish acts. They should have an on-line calendar soon. Sally Greenberg's House Concerts in Berkeley. They host a variety of music, but look for more Celtic acts in the future.
Headline acts frequently.
Sam and Barbara Summerscales. Henfling's Tavern in Ben Lomond has an exceptionally good selection of great Celtic musicians that do shows. Check the on-line calendar. Calendar of events is on their web site. For a list of Irish music sessions happening around the Bay, a good place to start is the Irish Music in San Francisco sessions page .