Question: What international Jewish non-governmental organization based in the United States did Frank Zappa deny an apology in 1979(?
Sentence (from "Jewish Princess (song)"): The song is a humorous look at the Jewish-American princess stereotype which attracted attention from the Anti-Defamation League, to which Zappa denied an apology, arguing: "Unlike the unicorn, such creatures do exist — and deserve to be 'commemorated' with their own special opus".
Relevant evidence: Yes