The Warlocks "Palo Alto High School" New Years 9/19/64 poster has been floating around for years. A company makes "commemorative" posters of past rock events, and you can usually get them for 10 or 20 bucks in record stores (remember those?).
For the record, Bill Kreutzmann actually graduated from Paly, and Pigpen
probably attended. There is a persistent rumor that the Warlocks
played, but the date keeps changing (Sep 19, 1965 has been floated),
which leads me to suspect that its wishful thinking. But hey, Santana
played the 1969 graduation dance (June 10, 1969--you can look it up).
Pigpen Ron McKernen was not exactly an alum, since he dropped
Jerry, as far as we know, never performed here.