On Jan. 3, 1969, the Kinetic artist known as Takis marched into the Museum of Modern Art. He entered an exhibition called “The Machine at the End of the Mechanical Age” and, with the help of several friends, removed his “Tele-Sculpture,” a compact work from 1960 involving two painted spheres attached to wires revolving around an electromagnet and a small motor.

Takis said he had not been asked about including the sculpture, which had been in the Modern’s permanent collection since 1962, in the show. He also said he took the action to “stimulate a more meaningful dialogue between museum directors, artists and the public,” according to an account in The New York Times the next day.

The incident sparked meetings among artists, critics, filmmakers, writers and museum staff. The meetings led to the creation of the Art Worker s ’ Coalition , of which Takis was a founding member.

Over its three-year existence, the coalition staged protests and lobbied museums to be more communicative with living artists whose work they owned; to be more open and inclusive, especially to artists of color and female artists; and to take a moral stand on the Vietnam War.