The All The Music project is something like that, but for melodies. They created all possible melodies of a 7 note diatonic scale and wrote them to disk as MIDI files, copyrighting them in the process. The melodies were dedicated to the Creative Commons Zero so that people could freely use them without worrying about being sued by someone else who had used that melody previously.

More details here: https://allthemusic.info/faqs/