VENUE: Seattle Center Arena, Seattle, WA DATE: April 19 1969 SECTION: Concert Poster TITLE: Frank Zappa / Mothers of Invention The Guess Who & Alice Cooper This psychedelic poster promoted a triple‑bill at the Seattle Center Arena featuring Frank Zappa and the Mothers of Invention, The Guess Who, and Alice Cooper. The event was presented by Boyd Grafmyre with KOL AM and FM. The artwork was created by John Moehring, known for his Pacific Northwest psychedelic style. The poster