Courtesy of Bedazzled, here's an amazing French pop festival film from June 1, 1967, entitled Le 1er Festival International de Pop Music, and laying claim too being the first big time rock-based festival. For a whole lot more on the event click on over to the post at Bedazzled. According to the author at Bedazzled, the date on the YouTube-posted video is incorrect.
Appearances at the festival included the pre-Spooky Tooth VIP's, Ronnie Bird, The Pretty Things, John "Maus" Walker (Walker Bros), Jimmy Cliff, Dave Dee, Dozy, Beaky, Mick & Tich, and the Troggs. Also playing, but not included in the film were Cream, Herbert Leonard, and Alain Bashung.