Damien Riehl, a musician, a lawyer, a coder, along with his colleague Noah Rubin have a project called All The Music which is based on the creation of an “application to generate by brute force all mathematically possible melodies and write them to MIDI files.”
Basically the duo created and then copyrighted a database of every single melody possible to create. Then they made all these melodies available to everyone.
This is perhaps the most specific and complicated part of the world of protest music there is.
“We’ve seen a flaw in the current copyright laws, described above, and we’d like that flaw to be remedied — to help songwriters. And since the current copyright laws result in uncertainty, we’d like our work to help increase certainty, allowing songwriters to make more music (with less fear of frivolous lawsuits).”
See more about the project here: http://allthemusic.info