Perhaps music that at least the author would listen to? To this day I haven't heard an AI song that made me wish I press the rewind/play to listen it again. Granted, most human-generated songs are crap, too, but at least they are not crap to their authors.

But aren't many crap songs popular too?

Doesn't seem like a good way to measure a "good song".

The eternal question.

I think in this context, the term "intentional music" or "earnest music" applies better. People who just wants "music that sounds good" already has mainstream stuff. Many who want a more niche sound deliberately look to support humans in that endeavor. Not yet another billionaire label who puts out "safe" but "boring" stuff. Except it's worse now.