The Phynx (1970) is not a good film but it is very entertaining. It’s someone’s idea of what would appeal to teenagers. It features an assembled band like the Monkees with songs by Leiber and Stoller.
It has an amazing cast of actors doing cameos. See this description from YouTube:
2,685 views Feb 12, 2024 What if a fictional rock band was recruited to play in a communist nation ? With Michael Ansara, Mike Kellin, Lou Antonio, George Tobias, Joan Blondell, Colonel Harlan Sanders, Xavier Cugat, Martha Raye, Ultra Violet, Pat McCormick, Rich Little, Maureen O”Sullivan, Johnny Weissmuller, Huntz Hall, Leo Gorcey, Ed Sullivan, Edgar Bergen and Charlie McCarthy, Sally Struthers, Dorothy Lamour, Andy Devine, George Jessel, Trini Lopez, James Brown, Dick Clark, Harold Sakata, Busby Berkeley, Patsy Kelly, Joe Louis, Guy Lombardo, Marilyn Maxwell, Richard Pryor, Jay Silverheels, Rudy Vallee, and Clint Walker.
It’s available on DVD from Warner Archive but I also found this full version above on YouTube.
Sad! 