Head
"Head" (1968) is an American rock movie starring the American pop group The Monkees. It features guest appearances by celebrities such as actors Teri Garr, Timothy Carey, Victor Mature, Annette Funicello, Jack Nicholson and Dennis Hopper, boxer Sonny Liston, film director Bob Rafelson, stripper Carol Doda and... Frank Zappa!
At the time Head was not a success, because the band's popularity was already waning at this point. Furthermore, the film is surreal with more adult comedy, which alienated most of their original teenage fanbase. Over the years Head has gained a cult following, though.
Frank Zappa
Frank Zappa has a small cameo in this film (around the 49:05 mark), leading a talking cow and giving David Jones some advice:
FZ: "That song was pretty white."
David Jones: "Yeah, well, so am I, what can I tell ya?"
FZ: "You've been working on your dancing though."
David Jones: "Oh, yeah, yeah, well, I've been rehearsing it. Glad you noticed that."
FZ: "Yeah. It doesn't leave much time for your music. You should spend more time on it, because the youth of America depends on you to show the way."
David Jones: "Yeah?"
FZ: "Yeah."