Hair was a landmark Broadway (see entry under 1900s—Film and Theater in volume 1) musical in the late 1960s. It was groundbreaking on several accounts. Hair not only portrayed the era's youth culture but also gloriously celebrated it. Its characters were way outside the mainstream of American society: They were hippies (see entry under 1960s—The Way We Lived in volume 4) who used drugs and shocking language. Hair relied on experimental theater techniques that focused on the themes of the musical and the portrayal of a lifestyle, rather than on character and plot development. Hair earned the distinction of being the first-ever rock musical. The cast members ignored the "fourth wall" of the theater—the invisible wall that separates actors and audience—by coming on stage from the audience, rather than from backstage. Finally, at the finale of the first act, during the celebrated "Be-In" sequence, the actors...