When “Hair: The American Tribal Love-Rock Musical” opened on Broadway, in 1968, it featured one of the best young casts ever to appear in an American musical. Diane Keaton, Melba Moore, and Ronnie Dyson were among the show’s stellar performers. The then twenty-two-year-old Keaton, in addition to having a little solo in “Black Boys,” was one of the few cast members who didn’t shed her clothes in the end. She didn’t see the point. Stories like this abound whenever the subject of “Hair” comes up. My own introduction to the musical was Miloš Forman’s 1979 movie version, with all those spectacular dances by Twyla Tharp, and that beautiful clown Annie Golden singing “Let the Sunshine In” into a cold winter sun.

What is it about this musical—which concerns a bunch of kids gathering in a park in New York’s East Village to welcome in the Age of Aquarius as one of their tribe goes off to war—that draws us to it, still? I think it has something to do with the co-lyricists James Rado and Gerome Ragni’s perfect melding of story and antiwar sentiment with Galt MacDermot’s music, some of which might remind you of Sonic Youth’s controlled disarray.

It’s been fifty years since the spectacle was born, at the legendary producer Joseph Papp’s Public Theatre, in 1967. To commemorate that milestone, La MaMa, another venerable downtown institution, is hosting a one-night-only anniversary celebration on Jan. 21, as part of its Coffeehouse Chronicles series, featuring cast members from that production at the Public, and others, from its first Broadway incarnation and elsewhere. Actors including André De Shields and Keith Carradine—who starred in the original and have turned up in other “Hair” productions throughout the years—will be on hand to sing such unforgettable songs as “Aquarius” and “Where Do I Go?,” and Rado and MacDermot will share stories. (Ragni died in 1991.) It will give the actors a chance to celebrate Rado’s eighty-fifth birthday, and to contemplate the days and years it took for Rado and his collaborators to find their true, defiant voice in the uncertain time of yesterday’s youth. ♦