Denver Pop Festival

The Denver Pop Festival was a three-day music festival promoted by Barry Fey (Feyline) on June 27–29, 1969 which was largely overshadowed by Woodstock two months later. The peak attendance was estimated at 50,000.
History.
Unlike the free-form happening in upstate New York, the Denver festival had the full support and local resources of a major city, taking place in Denver Mile High Stadium. There were high expectations for the Festival; it was commonly called the "First Annual" Denver Pop Festival. The peak attendance was estimated at 50,000, though on Sunday when it was declared a free festival, that number may have been higher. Ticket prices were $6 per day, or $15 for all three days (Fri, Sat, Sun).
Frank Zappa is credited by some with inventing the audience wave during his set. He assigned sections of the stadium (audience) to each make different odd sounds and gestures, including standing with arms raised. He then "played" a "tune" on his "crowd instrument".
The festival featured the final performance of The Jimi Hendrix Experience, then the highest paid act in rock. (Noel Redding left the Experience on June 29th, 1969.)