NEW YORK, NY.- Megan Terry, an Obie Award winner, a founding member of the Open Theater group and a prolific feminist playwright who wrote and directed a rock musical on the New York City stage that predated “Hair,” died April 12 at a hospital in Omaha, Nebraska. She was 90.

Elizabeth Primamore, a writer who is working on a book about Terry and four other women writers, confirmed the death Monday.

Terry’s “Viet Rock: A Folk War Movie” opened at Martinique Theater, an off-Broadway house, on Nov. 10, 1966, during the Vietnam War, after earlier performances at the Yale Repertory Company and La MaMa ETC, in the East Village.

The rock numbers’ lyrics were poignant and pointed: “The wars have melted into one / A war was on when I was born.” One song advised against optimism: “Don’t put all your eggs in one basket / Baskets wear out and men die young / Better to marry trees or elephants / Men die young.”

The dialogue played with politics and popular culture. “Let’s all go gay with LBJ,” one character said, a twist on President Lyndon B. Johnson’s campaign slogan “All the way with LBJ.” Others declared: “I lost my way with LBJ,” “March to doomsday with LBJ” and “I lost my green beret on the Road to Mandalay.”

“Viet Rock” was believed to be the first American stage work to address the Vietnam War.

“The piece ended with an image of rebirth,” critic Dan Sullivan wrote in the Los Angeles Times, “but the image that stayed with the viewer was a mound of dead soldiers, male and female, muttering ‘Who needs this?’”

The New York Times panned the production. Walter Kerr, the newspaper’s chief theater critic, dismissed it as “essentially thoughtless, from-the-gut-only noise.” The Village Voice called it extraordinary.

A year later, one of its cast members, Gerome Ragni, and two partners presented their musical “Hair” at The Public Theater, which moved to Broadway in 1968 and found overwhelming international success.

In her mid-30s, Terry went on to write “Approaching Simone” (1970), about Simone Weil, a French activist philosopher. It won the Obie Award for best off-Broadway play.

Jack Kroll wrote in Newsweek magazine that “Simone” was “a rare theatrical event” filled with “the light, shadow and weight of human life and the exultant agonies of the ceaseless attempt to create one’s humanity.” Clive Barnes of the Times called it “a superb theatrical coup.”

Marguerite Duffy was born July 22, 1932, in Seattle, the daughter of Harold and Marguerite (Henry) Duffy. Her father was a businessman. Marguerite became fascinated with theater after seeing a play at age 7 — a passion that, by her account, her disapproving father ridiculed, giving her nicknames such as Tallulah Blackhead and Sarah Heartburn, as opposed to Bankhead and Bernhardt.

In high school, she worked with the Seattle Repertory Playhouse, learning early that politics and theater could be powerful but prickly bedfellows. The playhouse closed in 1951 under pressure from the House Un-American Activities Committee.

Marguerite won a scholarship to the Banff School of Fine Arts in Canada, where she earned a certificate in acting, directing and design. Returning to her home state, she completed her bachelor’s degree in education at the University of Washington.

She then took a teaching job at the Cornish School of Allied Arts (now Cornish College of the Arts) in Seattle. Her first plays, including “Beach Grass” and “Go Out and Move the Car,” were criticized for their frankness, which led her to take two drastic steps.

She began doing her theater work under a pseudonym. Megan was the Celtic root of her first name, and Terry was a tribute to 19th-century British actress Ellen Terry. And she moved to New York City.

Her plays in New York included “The Magic Realist” (1960), “Ex-Miss Copper Queen on a Set of Pills” (1963), “When My Girlhood Was Still All Flowers” (1963), “Eat at Joe’s” (1964) and “Keep Tightly Closed in a Cool, Dry Place” (1967).

One of Terry’s most-talked-about techniques with the Open Theater, an experimental New York company founded in 1963 by Joseph Chaikin, was known simply as transformation. An actor might begin speaking in one language and suddenly switch to another, having taken on a new character’s identity.

In a scene in “Viet Rock,” one actor mimes being hit by gunfire and the others catch him. “Then, abruptly, the sounds change, the body is held high, and the group, rotating weirdly, has become a helicopter, transporting the wounded to Saigon,” critic Michael Feingold wrote in the Times in 1966. Seconds later, he wrote, the actors became the hospital, and “shortly afterward turn it, without a qualm, into a Buddhist funeral.”

The Open Theater’s last production was “Nightwalk” (1973), written by Terry, Sam Shepard and Jean-Claude van Itallie and performed in repertory with two other works. Mel Gussow of the Times called it “enormously enjoyable,” with a “strong and disquieting impact.”

Terry also worked with the Firehouse Theater in Minneapolis. In her 40s, she moved to Nebraska to become the playwright-in-residence at the Magic Theater in Omaha and continued to produce experimental work.

By the end of her career, she had written 70 plays. They include “Babes in the Bighouse: A Documentary Fantasy Musical About Life in Prison” (1974), “Sleazing Toward Athens” (1977), “15 Million 15-Year-Olds” (1983), “Dinner’s in the Blender” (1987) and “Breakfast Serial” (1991).

Much of her work was intended, at least partly, for young audiences. “The Snow Queen” (1991) was a playful adaptation of a Hans Christian Andersen fairy tale. “Headlights” (1990) was an examination of illiteracy.

Terry and five others co-founded the short-lived but influential Women’s Theater Council in 1972. She received the Dramatists Guild Award in 1983. Along with her wife, Jo Ann Schmidman, and Sara Kimberlain, she was an editor of “Right Brain Vacation Photos” (1992), an illustrated book of two decades of Magic Theater productions.

Terry is survived by Schmidman.

Saying goodbye was one of Terry’s least favorite activities. When she was getting her degree in education, she remembered the pain of losing the third grade class she had student-taught all year. In her career, she found a way to avoid that kind of enforced separation.

“I’ve always loved being in a theater company and being with people year after year,” she said in a 1992 interview at Wichita State University. “It satisfies my emotional needs and my intellectual needs. I come from a huge family, and theater gives you the chance to re-create the family in your own image.”

This article originally appeared in The New York Times.