I found these: https://www.quora.com/Why-are-there-only-12-pitch-notes-C-C-B-in-the-world https://www.quora.com/Why-are-there-only-12-pitch-notes-C-C-... http

I found these: https://www.quora.com/Why-are-there-only-12-pitch-notes-C-C-B-in-the-world https://www.quora.com/Why-are-there-only-12-pitch-notes-C-C-... https://www.quora.com/How-did-Western-music-settle-on-a-12-tone-scale https://www.quora.com/How-did-Western-music-settle-on-a-12-t...