This may be the earliest known live performance of the Quicksilver Messenger Service.Transferred from a cheap 1980s cassette which was labeled as The Matrix, SF, mid '66. Information on the Internet narrows the date down to August 9-10, 1966. There are several cuts in the tape, so it could be from both dates.
Possibly confirming this as an early show, are the lyrics to track 14. "Hair Like Sunshine" is on several other Quicksilver recordings, but on this one, the lyrics are completely different for the first part of the song: no Hair Like Sunshine, for example. The second part of the song is as usual. The source tape had tracks 7-16 as Side A and tracks 1-6 as Side B they're switched; seems more correct with the incomplete Mona at the end. Tracks 1-6 sound slightly better too.
Recording quality is listenable but not great. This is a very primitive stereo soundboard tape. The main problem is lack of treble combined with an abundance of hiss.