I take your code and I compress it in a tar.gz file. Il call that file "the model". Then I ask an algorithm (Gzip) to infer some code using "the model". The algorithm (gzip) just learned how to code by reading your code. It just happened to have it memorized in its model.

With the exception that there are infinite types of chords in this case, and even though many musicians follow familiar chord structures the underlying melodies and rhythms are unique enough for any familiar person to be able to differentiate "Red Hot Chill Peppers" from "All-American Rejects", and now there is a system where All-American Rejects hit a few buttons and a song is generated (using audio samples of "Under the Bridge") that sounds like "Under the Bridge pt 2, All-American Rejects Boogaloo".

That's why it's actionable and why there is meat on the bone for this case. The real issue is going to be if they can convince a jury that this software is just stealing code and whether its wrong if a robot does it.