> What's obviously missing is a "fitness function" that can approximate the equivalent of human taste, so the final evolved forms just end up being widely random in terms of quality.

Honestly for me this is a feature not a bug. If I want to hear music that matches my personal taste exactly I can just go to my instrument and play it. These tools are a way to taste more exotic forms and see if there's anything worth carrying over.

And that's perfectly fine.

But when we conceptualize something like music in the form of evolutionary computation then it is important to be able to define a good metric for the fitness function otherwise you might as well just take X pieces of music, normalize them to the same key signature/tempo/etc., and then randomly mash them together.

If you're just in the mood for something more exotic, I'm happy to go repeatedly sit on my piano for a few hours and send you the final samples.