Original 1st printing 14 x 20" concert poster for Big Brother & the Holding Company (featuring Janis Joplin) appearing at the Matrix in San Francisco, CA from 1/31-2/5/1967. Art by Victor Moscoso, image is # 4 in the Neon Rose series. Medium flat index stock poster (OP-1 in Eric King's book) is in near mint to excellent (A-/B+ to B+) condition; just a trace amount of corner/edge wear (a couple of tiny mouse bites along the extreme bottom left edge, a pair of bumps/tiny bends in the top left/right corners and a stray pinch ding or two), otherwise fine. An EXTREMELY bright, eye-searing example of this somewhat hard-to-find Moscoso/Neon Rose poster with a really neat design.