Harry Partch has a book Genesis of a Music, which is half autobiography and half a theory that all melody derives from the micro pitch variations of speech - as

Harry Partch has a book Genesis of a Music, which is half autobiography and half a theory that all melody derives from the micro pitch variations of speech - as in melody is a stretched out version of how we speak. I don't know if this idea has ever been pursued more academically but I find it very interesting. If it's true, I also wonder if there's feedback, like our vocal inflections are influenced by music melodies just as much as vice versa.