The duo built a simple system working with MIDI, the computer music framework, and started outputting melodies. They’d wanted to generate all possible melodies on the piano, but after some prototyping, settled for 12-note melodies in a popular range that Riehl had seen implicated in copyright litigation: the octave ascending from middle C. Even to complete this set, Rubin had to switch programming languages (from Python to Rust), he said, “and that gave us the speed increase we needed.” Soon, they had a hard drive filled with almost 69 billion melodies. In a conversation with Adam Neely, a YouTuber who helped spread the word about the project, Riehl alluded to previous copyright thought experiments. “This has been a concept that has been discussed,” he said. “But no one has ever brute-forced [it] in this way.”

Now Riehl and Rubin want to release the fruits of that brute-forcing into the public domain. They figure that in a future suit where a musician is hit with copyright infringement, she could point back to the melody on that hard drive as her uncopyrighted inspiration. Their point, ultimately, is that melodies could be seen as math, which is to say facts, and facts cannot be copyrighted. This is not to say that songs cannot be copyrighted, but that each possible series of notes is not a creation so much as a selection from a fairly limited set. (Information theorists might add that selection from a set of possibilities is the very nature of all information—but that’s beyond the theoretical scope of the melody project.)