The "creative" aspect is what's important. Designing the sprites, backgrounds, art styles, etc of a videogames is creative.

It's harder to argue that brute force generating every single possible sequence of musical notes is creative.

I guess you can make the argument that coding up the solution that does the generating of the music is the creative part here, just as with games where the creative process is creating the environment for example.

I guess music that is made by programming is just as copyrightable as "normal" music. With Ableton/Max Live and similar, programming and music production is getting closer and closer to each other anyways.

What is or isn't "significantly creative" will ultimately be left for a jury to decide. Even though the code might have involved significantly creative elements, that does not automatically imply that the program's output also includes significantly creative elements.

A list of all possible permutations of anything isn't creative, regardless of how it was generated.

"I guess you can make the argument that coding up the solution that does the generating of the music is the creative part here"

They unambiguously have a copyright to whatever software they wrote to create this output. You do not in general get copyright to the output of software, though. (You may in specific. I'm not getting too detailed here. But you definitely do not in general.)