Noam Chomsky's theory, set out in 1957, that a finite set of rules can generate every sentence of a language. Early computer poetry and generative art drew on it.
Generative grammar was defined by Noam Chomsky around 1955. He was more or less alone, claiming that there are generative mechanisms in grammar.
Frieder Nake, Frieder Nake on “Machinic” Miracles
Chomsky showed how the concept of grammar could create rules that allow you to automatically generate correct sentences.
Frieder Nake, Frieder Nake on “Machinic” Miracles