The poster says Winterland. The show happened at the Fillmore. That gap is the whole story of BG-30A.

In early October 1966 Bill Graham had begun renting Winterland — a cavernous former ice rink on Post Street — for bills too big for the Fillmore Auditorium's roughly 1,200 capacity. The Butterfield Blues Band, Jefferson Airplane and the Grateful Dead were booked there for Friday and Saturday, October 7 and 8. Wes Wilson drew the poster. It went up around the city advertising Winterland.

Then the shows moved back to the Fillmore.

Graham had jumped venue sizes faster than ticket sales justified, and the Winterland dates were pulled at short notice. The bill played the Fillmore Auditorium instead — and because the smaller room could not hold the demand the larger one had been booked for, Graham added a third performance: a Sunday afternoon concert on October 9, starting at two o'clock. BG-30A is the artifact of that addition. The Grateful Dead's own archive lists it plainly: Fillmore Auditorium, October 9, 1966, afternoon concert at 2:00 PM, billing Butterfield Blues Band, Jefferson Airplane, Grateful Dead.

Note the billing order, because it is not the one a 2026 reader expects. Paul Butterfield headlined. The Jefferson Airplane were second. The Grateful Dead — a year from their first album, two from Anthem of the Sun — were the opener. In October 1966 the Butterfield Blues Band were the established act on that stage: Chicago blues players with two records out and a national reputation, the band that had backed Dylan at Newport the summer before. The San Francisco groups beneath them were still local concerns. Within eighteen months the hierarchy would invert completely, and the poster collectors who grade BG-30 today mostly want it for the two names at the bottom.

The Sunday matinee itself was a Graham pattern worth understanding. Afternoon shows let in the people a late Friday night excluded — younger fans, people without cars, anyone whose parents were not going to permit a midnight return from the Fillmore district. Graham ran them not out of sentiment but because an empty hall on a Sunday afternoon earns nothing, and because the mailing list he was building depended on reaching exactly those people. The second-show postcards and handbills in the numbered series, the ones carrying an "A" suffix, are the paper trail of that habit.

What makes BG-30A worth its own entry rather than a footnote to BG-30 is precisely what makes it awkward: it documents a show that the poster it belongs to does not describe. Collectors catalog it under the Winterland image. The audience who attended it walked into the Fillmore on a Sunday afternoon. Both facts are true, and a catalog that recorded only the first would be recording the advertisement rather than the event.