They opened for Creedence Clearwater Revival. You can see members of of CCR groovin' in the wings while they rip through a hot version of "Time Is Tight". This was filmed for an ABC TV Special. I have the whole thing on an old bootleg VHS tape that I bought years ago at the Emeryville record swap. In addition to CCR's set they also show them and the MG's jamming together at "The Factory", their Berkeley rehearsal studio. Footage like this should be released officially. R.I.P Al Jackson Jr.