In June 1966, Bill Graham did something he almost never did at the Fillmore: he put a comedian at the top of the bill. BG-13, the thirteenth poster in his numbered series, advertised "Lenny Bruce and the Mothers" across two nights — Friday and Saturday, June 24 and 25, 1966. Wes Wilson built the design in burning orange and purple around a photographic portrait of Bruce shot by Edmund Shea. Among the early Fillmore posters, nearly all of which fronted musicians, BG-13 stands apart for who it sold: not a band, but the most embattled satirist in America, sharing the stage with Frank Zappa's Mothers of Invention.

The booking carried weight no one in the room could fully measure. By 1966 Bruce had been chased through obscenity trials and effectively blacklisted from the nightclub circuit; these Fillmore dates were rare paying work. They were also, as it turned out, the last performances he would ever give. Roughly six weeks later, on August 3, 1966, Lenny Bruce was found dead at his home in the Hollywood Hills, an overdose. He was forty.

The performances were not the valediction nostalgia might wish for. Graham, who was there, recalled in his memoir a performer "whacked out on amphetamine" who finished his set emotionally disturbed — daring more than triumphant. That tension is exactly why BG-13 endures: a beautiful object advertising a diminished final act by a man who had spent his career insisting the difficult things be said aloud. It is collected today for its design and its rarity, but its real charge comes from the date printed on it.