Hair is a 1979 musical anti-war comedy-drama film directed by Miloš Forman and adapted for the screen by Michael Weller, based on the 1968 Broadway musical Hair: The American Tribal Love-Rock Musical. Set against the backdrop of the hippie counterculture of the Vietnam era, the film focuses on a Vietnam War draftee who meets and befriends a “tribe” of hippies while en route to the army induction center. The hippies and their leader introduce him to marijuana, LSD, and their environment of unorthodox relationships and draft evasion.

https://en.wikipedia.org/wiki/Hair_(film)