A Monkees concert that had been scheduled for May 27, 1967 at the Spartan Stadium in San Jose, California was later canceled after Mike had his tonsils removed on May 23. This is a poster advertising the original event. In Marty Eck's 1998 book The Monkees Collectibles Price Guide, it was estimated to be worth $400 if you possessed a near mint copy of it.
Poll # 1: Vote!
Poll #2: Vote!