Another snippet from Curtis Roads' book Composing Electronic Music: A New Aesthetic, on the topic of the conventionality of Western melodic forms:
Conventional classical and popular styles exhibit a great deal of redundancy in melodic patterns (i.e., parts of many melodies are identical). The tendency of composers to borrow or reinvent an existing tune has been long studied by musicologists. As Thomas Alva Edison (1917) once observed: "I had an examination made of the themes of 2700 waltzes. In the final analysis, they consisted of 43 themes, worked over in various ways." [citations omitted]
You gotta love that hubris of the dilettante one-percenter: "I had an examination made..." What are servants for, after all. If only Bill Gates would examine 2700 waltzes instead of mucking about in charter schools; the world might be a better place. He could even have interns doing it.