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

 Art 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 very good to excellent (B/B+ to B+) condition; there are tack holes in the upper left margin, top left margin, top right image border corner tip and in the lower right image border corner tip, along with a few soft surface stains along the lower right margin (under "9:00 PM"), a bit of creasing, light surface dirt/smudging a couple of tiny nip tears along the upper right margin, a couple of hairline-thin/nearly-invisible thin horizontal roll bends/stress creases hiding within the image area and a tiny pin-prick drip spot  just above Wes Wilson's signature in the lower right margin, otherwise fine. 

 Most of the conditional issues on this example are limited to the outer edges of the poster, the image area is REALLY sharp- bright colors, perfect registration, no toning or fading... a BEAUTIFUL specimen.