[cbd1984]

> They're alike enough that you could probably make a mashup with just those few chords and it'd sound nice, but the entire rest of the songs are utterly different.

To amplify your point:

You can mash up "Hot In Here" by Nelly and "Stayin' Alive" by the Bee Gees and that sounds good. (In that: Even if it isn't your taste in music, it works in some objective sense. It sounds like what that kind of music is supposed to sound like. Can you tell I don't know anything about music theory?)

https://www.youtube.com/watch?v=ekwod6Py1RI

Anyway, my point is that on a basic, mechanical level, all music is derivative. That's part of what a 'genre' is. That's part of what a 'musical tradition' is, why Mozart sounds different from Chinese Opera.

Infringement has to be based on something more.