Marcel Duchamp (1887–1968) was a French painter, sculptor, and chess player.
I think Duchamp said, "Le regard fait le tableau." It is the look that makes the painting. We're ultimately making art for it to be completed by a public.
Rafael Lozano-Hemmer, 2020s On-Chain Art: Erick Calderon, Lauren Lee McCarthy
We can, of course, go back a lot longer in music and language, but I think the twentieth century was all about the origins of generative art. It goes back to Marcel Duchamp.
Casey Reas, Casey Reas on the History of Generative Art - Part 1