Fun trivia about piano rolls and copyright which us software nerds might find interesting:

"White-Smith Music Publishing Company v. Apollo Company, 209 U.S. 1 (1908), was a decision by the Supreme Court of the United States which ruled that manufacturers of music rolls for player pianos did not have to pay royalties to the composers."

"The main issue was whether or not something had to be directly perceptible (meaning intelligible to an ordinary human being) for it to be a "copy."

https://en.wikipedia.org/wiki/White-Smith_Music_Publishing_C...