This intriguing clipping from the entertainment column in the San Mateo Times of December 8, 1967, has the following intriguing quote
Making a big hit with the early Sunday evening dancing crowd is the special $1.25 dinner at the Rock Garden on Mission near Ocean Avenue, in San Francisco. The dinner and dancing to the great Tracy Brothers combo begins at 6 p.m., with minors welcome. Talent auditions for recording contracts are another popular Sunday Rock Garden feature
Although the location is not precise, this is almost certainly the same Rock Garden that was briefly a psychedelic rock venue for several weeks in March and April 1967, featuring Big Brother, The Grateful Dead and the Buffalo Springfield, among others. An April show featuring Country Joe and The Fish seems to have been canceled, and nothing surfaced afterwards about the club. Further research revealed that it turned into a club called The Ghetto, featuring Soul and Latin music, and that it was a foundational venue for the Latin Rock explosion in San Francisco that culminated with Santana and Malo breaking out onto the National scene.
When I wrote about the venue earlier, I made the point that when a Use Permit is in force, its easier for a promoter to use an existing entertainment venue rather than create a new one. Whoever the owners or promoters behind the original Rock Garden might have been, the club seems to have had a post-psychedelic period before it became The Ghetto. The Tracy Brothers are unknown to me--I wonder if anyone got a recording contract from the auditions? I am still searching for who might have been performing at The Rock Garden on nights other than Sunday.
While the San Mateo Times was a suburban newspaper, the Rock Garden was more accessible to much of the South Bay suburbs than it was to downtown San Francisco. The South Bay's main "strip," El Camino Real, turned into Mission Boulevard in San Francisco. A South Bay resident could drive up El Camino to Mission without having to go over the substantial hills between the Excelsior District and Downtown, so it makes sense that the interregnum Rock Garden was aiming for a suburban appeal.