August 14 catches two very different Fillmore West nights a year apart, and the pairing is almost too neat: in 1968 the future of rock volume (The Who, second of three nights under BG-133, with James Cotton and Magic Sam again below them — per billgrahamfoundation and thewho.com); in 1969, its founding father. For the week of Aug 12–17, 1969, David Singer's BG-187 poster (per famsf and wolfgangs, which credit Singer and list the full bill) put Chuck Berry at the top of a split-billed card — Berry, Jethro Tull, and The Loading Zone on the early nights, Chicago Transit Authority, the Youngbloods, and Colosseum on the later ones. Wolfgang's describes BG-187 explicitly as a "split-billing poster"; the exact per-night division (Berry's trio on Aug 12–14, the CTA trio on Aug 15–17) rests on a single archival reading and should be treated as likely rather than settled. On Thursday the 14th, Berry — duckwalking through the room that psychedelia built, a decade after "Maybellene" — headlined the older, plainer rock-and-roll the ballroom kids had descended from.

That the 14th of August could hold The Who in one year and Chuck Berry the next, in the same room, is the whole compression of the era in a single date on the wall.

(One contested detail carried for the human gate: a lone community listing says Jethro Tull cancelled the Aug 13 night; it is uncorroborated and is NOT asserted here.)