Hair: The American Tribal Love-Rock Musical is a rock musical with a book and lyrics by James Rado and Gerome Ragni and music by Galt MacDermot. A product of the hippie counter-culture and sexual revolution of the 1960s, several of its songs became anthems of the anti-Vietnam War peace movement. The musical's profanity, its depiction of the use of illegal drugs, its treatment of sexuality, its irreverence for the American flag, and its nude scene caused much comment and controversy. The musical broke new ground in musical theatre by defining the genre of the "rock musical", utilizing a racially-integrated cast and inviting the audience onstage for a "Be-in" finale.

Hair tells the story of the "tribe", a group of politically active, long-haired "Hippies of the Age of Aquarius" fighting against conscription to the Vietnam War and living a bohemian life together in New York City. They struggle to balance their young lives, loves and the sexual revolution with their pacifist rebellion against the war and the conservative impulses of their parents and society. Claude, one of the leaders of the tribe, must decide whether or not to resist the draft, as his friends have done.

After an off-Broadway debut in October 1967 at Joseph Papp's Public Theater and another run in a midtown discothèque space, the show opened on Broadway in April 1968 and ran for 1,750 performances, followed by a successful London production, which ran for 1,997 performances. Numerous productions have been staged around the world since then, and numerous recordings of the musical have been released. Several of the songs from its score became Top 40 hits, and a successful movie adaptation was released in 1979.