Future Sons of Champlin road manager Charlie Kelly saw this show and told me about it in a personal email. He was an Army draftee at the time, and he had a memorable week’s leave, where he celebrated his 21st birthday at the Avalon seeing his High School friends band, The Sons of Champlin. Kelly would join the Sons crew when he returned from the Army in mid-1968. He also recalls seeing the Dead for the first time at this show.
Given what a memorable week this was for Kelly, I do not lump this show under the “vague memories” category. Kelly recalls that this was some kind of pep rally in the gym. There is a chance it was on December 15 (Thursday). Kelly recalls that he wasn’t that impressed with the Dead’s performance.
In 1966 and 1967 bands like The Grateful Dead and Quicksilver Messenger Service, while popular Fillmore headliners, were just getting by financially. Any paying gig was welcome, and high school and junior college gigs paid a few hundred bucks, making the show well worth it. Presumably the Dead played the type of numbers heard on the Rare Cuts and Oddities cd.