Also worth adding another caveat that the 12-tone equal tempered musical scale that most of the world uses these days is used because those notes give you a pre

Also worth adding another caveat that the 12-tone equal tempered musical scale that most of the world uses these days is used because those notes give you a pretty reasonable approximation of most of the small whole-number frequency ratios that sound most consonant. But there's no reason a melody has to restrict itself to just those notes. In particular, ratios that have a 7 in them somewhere are very poorly approximated in 12-tone equal temperament. The number of pitch intervals is theoretically infinite, but as a practical matter if a pitch is close to another it's likely to be mistaken for it. If we suppose that the threshold for a note to be different enough in pitch to be distinguished as a different note in a certain context is, say, five cents, then that gives us about 240 unique notes per octave. That's a bit of an oversimplification, but anyways the point is there's more than 12 notes, and music is like a vast continent with a thriving metropolis in one small corner but the vast majority of the land has never had more than a cursory exploration, if that. Here's a list of pitch intervals that were deemed interesting enough to be included in wikipedia: https://en.wikipedia.org/wiki/List_of_pitch_intervals https://en.wikipedia.org/wiki/List_of_pitch_intervals