On Friday, October 6, 1967, the Avalon Ballroom opened a three-night weekend around the loudest young band in San Francisco: Blue Cheer, the power trio then building a reputation as the most physically overwhelming act in the city, headlining through Sunday the 8th with Lee Michaels, Clifton Chenier, and North American Ibis filling out the bill (per chickenonaunicycle's Family Dog list, the museum catalogs at the Albuquerque Museum and the Zurich University of the Arts, and the dealer rockposters.com, which all give the October 6-8 dates and the catalog number FD-86).

Blue Cheer in the autumn of 1967 were a few months shy of the single that would make them briefly famous — their fuzz-drenched demolition of Eddie Cochran's "Summertime Blues," cut that winter for the "Vincebus Eruptum" album. On this Avalon weekend they were still a local phenomenon more than a national one: Dickie Peterson, Leigh Stephens, and Paul Whaley, a trio who had decided that the way forward was simply more volume than anyone else was willing to attempt. The scene around them had opinions about that. Blue Cheer's name turns up again and again on Family Dog bills through 1967 and 1968 — the COAU Avalon list alone shows them sharing stages with Big Brother, the Charlatans, Captain Beefheart, and Country Joe across the season — which is to say the Avalon was comfortable giving them top billing by October.

Underneath them the bill is a genuinely odd and lovely cross-section of the moment. Lee Michaels, the second act, was the organ-and-drums one-man-plus-drummer powerhouse who was a reliable Avalon draw in his own right. Then comes the detail that makes FD-86 worth stopping on: Clifton Chenier, the Louisiana "King of Zydeco," his accordion and washboard squarely out of the Gulf-Coast Creole tradition, dropped into the middle of a San Francisco acid-rock weekend. That booking is pure Chet Helms and pure Family Dog — the same instinct that had already put Lightnin' Hopkins and Howlin' Wolf and John Lee Hooker in front of ballroom crowds, treating the blues and its cousins not as a museum piece but as part of the same living music the light shows were built on. North American Ibis, the bottom act, is the obscurity of the four; the name survives mainly on the poster, and I'll resist the temptation to claim more about them than the sheet does.

The poster itself is where this date earns its place on the calendar, and it comes with a correction worth making loudly. FD-86 is the work of Victor Moscoso — and Moscoso alone. His copy is one of the great examples of the style that made him: the image is a bank of red flowers in a blue vase on a red table against black, with the concert's text not set beside the picture but woven directly into the petals, pushed right to the edge of legibility in the vibrating complementary color he was famous for. Moscoso signed the dealer-grade copies in silver ink. The Albuquerque Museum, Zurich University of the Arts, the San Francisco Museum of Modern Art, and the Museum of Fine Arts Boston all catalog FD-86 within their Moscoso holdings, with no competing attribution anywhere.

Which brings up the artifact this page is partly here to kill. The chickenonaunicycle Family Dog list records the FD-86 designer as "Clifton Chenier, Victor Moscoso" — as if Chenier, the zydeco accordionist, had somehow co-designed a psychedelic poster. He did not. That is a data-entry slip in which the last-billed performer spilled into the designer column; Chenier belongs on the bill, not the art credit. Every reachable museum and dealer source credits Moscoso as the sole artist, and the four-act bill (Blue Cheer / Lee Michaels / Clifton Chenier / North American Ibis) shows exactly where Chenier really sits. If anyone builds this day, the designer field reads Victor Moscoso, full stop.

A word on where FD-86 sits in the sequence, since the surrounding numbers are easy to trip over. FD-85 is the weekend before — Vanilla Fudge with the Charles Lloyd Quartet, September 29-October 1, already a live row in the collection — and FD-87 is the weekend after, Buddy Guy with Captain Beefheart and (again) Blue Cheer, October 13-15. FD-86 is the October 6-8 Blue Cheer weekend, squarely between them, and the catalog order corroborates the date rather than complicating it. Because FD-85's run ends October 1, its poster does not reach into October 6, so there is no catalog-collision risk on this day.

One more thread, offered carefully. Across town the same Friday night, the Matrix — the little Fillmore Street club that had launched half the scene — was hosting Big Brother and the Holding Company with Janis Joplin, and the Family Dog chronicle (via COAU) notes a police raid on the Matrix that night. October 1967 was a bust-heavy season in the Haight: the Grateful Dead's house at 710 Ashbury had been raided on October 2, and the Straight Theater notes record a Blue Cheer-connected house bust in the same stretch. The Matrix raid is corroborated in outline — the club did close briefly in 1967 after a raid during a Big Brother show — but I could not independently confirm the exact October 6 date beyond the COAU entry, so it belongs in this story as atmosphere and a thread for a human to chase, not as a load-bearing claim. The anchor for the day is firm: Blue Cheer at the Avalon, Moscoso's flowers, FD-86.