Simone Forti, the movement artist whose 1961 Dance Constructions laid the groundwork for postmodern dance, died on July 29 in Los Angeles. She was 91.

Forti performed the Dance Constructions — a set of interdisciplinary works including Slant Board, Huddle, and Hangers — in Yoko Ono's loft on Chambers Street in 1961, a year before the founding of Judson Dance Theater, the movement often credited as the big bang of postmodern dance. The pieces merged functional movement with objects. Yvonne Rainer and Steve Paxton, both of whom performed in those works, absorbed their influence directly. As Rainer said later, "Simone was [Judson Dance Theater's] inspiration and fountainhead. We all owe her."

Forti's works entered museum collections, including the Museum of Modern Art, and she showed with Galleria Raffaella Cortese in Milan. She wrote prolifically, contributing often to Contact Quarterly over the decades.

Born into a Jewish family in Italy in 1935, Forti fled fascist Italy with her family at age 3; they settled in Los Angeles by the time she was 5. She attended Reed College, where she met and soon married the future minimalist sculptor Robert Morris. Both were abstract expressionist painters then, and together they entered the experimental orbit of Anna Halprin in the Bay Area. With an agile body and a witty outlook, Forti embraced the improvisational nature of Halprin's activities on her outdoor deck.

Forti and Morris moved to New York in 1959. In 1960, Forti joined — along with Rainer and Paxton — the new class in dance composition taught by Robert Dunn, a disciple of John Cage, at the Merce Cunningham studio. Recalling those days, Forti wrote in Movement Research Performance Journal #14: "Back then, making a piece was like brushing away all the sand and debris to reveal one stone."

Dunn's class, which soon included Trisha Brown, Lucinda Childs, Elaine Summers, Deborah Hay, and visual artists Robert Rauschenberg and Alex Hay, generated so much new work that the group began showing pieces at Judson Memorial Church in 1962 — an under-the-radar band of rebels reshaping concert dance.

Forti did not join the Judson collective. Instead she performed in the happenings-style theater work of her second husband, the artist Robert Whitman. She resumed her own work in 1966. Two years later, drawing on her visits to the zoo, she adopted various animals' gaits in her "zoo mantras" — serious crawling, banking in circles, swaying like a polar bear. In her "news animations," she might clutch or caress parts of her body to indicate mountains and rivers.

She developed powerful improvisational skills, capable of being sensuous and funny at once. In the 1980s she formed a small group that included David Zambrano and K.J. Holmes, both leading improvisers today. A 1995 clip of her improvised duet with Zambrano shows how responsive and daring she could be: vocalizing and storytelling erupt from the dancing as their impulses meet or collide.

Forti gave hundreds of performances and workshops over six decades, across dozens of countries. Throughout, she also drew, painted, made sound recordings, and invented other forms, like her "face tunes" — sounds derived from the outlines of people's faces.

Her first book, Handbook in Motion, is a sui generis memoir. In a prose-poem style as elemental as her dancing, she explains how she arrived at her aesthetics. Coming to New York from California, she was appalled by all the concrete and skyscrapers. "I remember how refreshing and consoling it was to know that gravity was still gravity," she writes. "I tuned into my own weight and bulk as a kind of prayer."

The recognition came steadily. Forti received the Yoko Ono Lennon Courage Award for the Arts in 2011, and honors from Movement Research in 2014 and Danspace Project in 2019. The Museum der Moderne in Salzburg mounted a full retrospective in 2014, as did the Museum of Contemporary Art in Los Angeles in 2023. That same year, Wayne McGregor, artistic director of the Venice Biennale dance festival, presented her with the Golden Lion for Lifetime Achievement in Dance.

Rainer's tribute places Forti at the source of a tradition that rewrote the rules of concert dance — one whose repertory, from Huddle to Slant Board, continues to be performed and studied in museums and studios worldwide.