The film stars an ensemble cast including John Savage, Treat Williams, Beverly D'Angelo, Annie Golden, Dorsey Wright, Don Dacus, Cheryl Barnes and Ronnie Dyson.

The tribe members—LaFayette "Hud" Johnson, Jeannie Ryan (who is pregnant) and "Woof Dachshund"—crash a private dinner party to introduce Claude to Sheila, who secretly enjoys her rigid environment being disrupted ("I Got Life").

They subsequently attend a peace rally in Central Park, where Claude drops acid for the first time ("Initials", "Electric Blues/Old Fashioned Melody", "Be In").

Claude's "trip" reflects his inner conflict over which of three worlds he fits in with: his own native Oklahoman farm culture, Sheila's upper-class society, or the hippies' free-wheeling environment.

"), Claude finally reports to the draft board (“Black Boys/White Boys”), completes his enlistment, and is shipped off to Nevada for basic training.

Sheila proceeds to chat up army sergeant Fenton at a local bar, luring him to an isolated desert road where the hippies acquire his uniform and car.

Claude returns to the empty barracks and frantically pursues Berger's plane but is unable to reach it before it takes off for Southeast Asia ("The Flesh Failures").

[3] All lyrics are written by Gerome Ragni, James Rado; all music is composed by Galt MacDermotRonny Dyson and Melba Moore, both from the Broadway version of Hair, both sing on "Three Five Zero Zero".

[6] Ragni and Rado stated, "Any resemblance between the 1979 film and the original Biltmore version, other than some of the songs, the names of the characters, and a common title, eludes us.

The critical consensus reads, "Spiritedly performed by a groovy cast and imaginatively directed by Milos Forman, Hair transports audiences straight to the Age of Aquarius.

"[9] For The New York Times, Vincent Canby called it "a rollicking musical memoir.... [Michael] Weller's inventions make this Hair seem much funnier than I remember the show's having been.

"[10] Frank Rich said: "If ever a project looked doomed, it was this one" (referring to the "largely plotless" and dated musical upon which it was based, Forman's and Tharp's lack of movie musical experience, the "largely unproven cast" and the film's "grand budget"); but that in spite of these obstacles, "Hair succeeds at all levels—as lowdown fun, as affecting drama, as exhilarating spectacle and as provocative social observation.

It achieves its goals by rigorously obeying the rules of classic American musical comedy: dialogue, plot, song and dance blend seamlessly to create a juggernaut of excitement.