Beck performed a lot at Al's. This particular 1992 show had him performing acoustically between other bands. Beck apparently played a song called 'Gilligan's Island Blues'.
In 2019, one of the top lining bands (Permanent Green Light) posted the flyer for this show on their Instagram.
(I'm not 100% if the note about 'Gilligan's Island Blues' is from this show, but it matches both the venue and the top two bands, so I will for now assume it is it.)
Anybody with more info on this, please e-mail me