British band Them (led by Van Morrison) made their first local appearance at this concert. Also appearing, The New Tweedy Brothers had the Haight-Ashbury spirit but never broke out of the San Francisco sound. Wes Wilson continued his experimentation with poster design, and the undulating 'picture frame' form suggests liquid light show splash effects.
The postcard was printed after the concert with the 2nd printing of the poster and has union logo 183 in the center of the bottom margin. It measures 5" x 7".
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.