We'll try to support modding of some sort. We can't make any promises, it's never been on our list of things we need to do, but we'll try. Would be great! And it's a fantastic idea.
As I said, I'm willing to write the (preliminary as of course, it'd have to be assessed/reviewed/testedToHell/accepted/integrated), code for the music pick up if development time is at a premium. It'd help shave some time off anyway and distract the dev team less.