Original 1st (and ONLY) printing 14 x 20" concert poster for the Grass Roots appearing with Big Brother & the Holding Company (pre-Janis Joplin) and Sons of Adam at the Avalon Ballroom in San Francisco, CA  from 4/29-30/1966. *shows were cancelled

 Art by (and SIGNED in pencil by) Wes Wilson (central image borrowed from Franz (Von) Stuck), image ("Sin Dance") is # 6 in the Family Dog/Avalon series.

 Medium flat vellum stock poster is in near mint to excellent (A-/B+ to B+) condition; aside from a VERY soft hint of smudging just to the left of Wes' signature and a couple of nearly-invisible pressure dings around the outer margin area, it is an absolutely SPARKLING-clean ARTIST-SIGNED example of this iconic early Family Dog image.