BG026 is Wilson's first poster to incorporate a nude portrait of his wife Eva, although the unclad female form would soon become a recognizable feature of his work. Motown legends Martha and the Vandellas were a new addition to the San Francisco fare of The Jefferson Airplane and The Grateful Dead.
The 1st printing was done before the concert on thin stock, and the colors vary substantially within the press run. These originals can be distinguished from the reprints by the absence of the "#26" which appears after "Wes Wilson '66". It measures 13 3/8" x 20 7/8".
The 2nd printing bears "#26" after the "Wes Wilson" credit, and the colors vary within the printing as does the poster thickness, which ranges from .0075" to .008". The "26" ranges from deeply etched to barely visible. The poster was printed after the concert and measures 13 3/8" x 20 7/8".
The post-concert 3rd printing displays the "#26" after the Wilson credit and is on .009" thick stock. The black background is fibrous and splotchy, and it measures 13 3/8" x 20 13/16".
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.