Wes Wilson returned to the Graham stable for two more posters, BG150 and BG151. Both of them faces, BG150 represented a person in turmoil, and the New Testament verse, "This house divided is against itself," spoke to conflict. The verse referred more to Wilson's relationship with Bill Graham than it did to the performing artists, Santana and Grass Roots.
The postcard was only printed once before the concert. It measures 4 5/8" x 6 1/2".
There were also some pre-concert mailers printed that were conjoined with the BG151 image. They measure 7" x 9 3/16".
When the Avalon Ballroom and Bill Graham's Fillmore Auditorium began to hold weekly dance concerts, Wilson was called upon to design the posters. He created psychedelic posters from February 1966 to May 1967, when disputes over money severed his connection with Graham. Wilson pioneered the psychedelic rock poster. Intended for a particular audience, "one that was tuned in to the psychedelic experience," his art, and especially the exaggerated freehand lettering, emerged from Wilson's own involvement with that experience and the psychedelic art of light shows.