Other people have good answers to this question in this thread, but here's my attempt at the beginnings of a programmers introduction to music theory: https://

Other people have good answers to this question in this thread, but here's my attempt at the beginnings of a programmers introduction to music theory: https://github.com/abetusk/scratch/blob/release/notes/Music-Theory.md https://github.com/abetusk/scratch/blob/release/notes/Music-... voting749227383 has a good response but to elaborate on the 12 note choice more, there's some justification of why 12 as opposed to some other number [0]. 12 notes gives a good compromise of the ability to combine notes in the scale while still not being too large to be unwieldy. In other words, some large ratio of note pairs have frequency ratios with small numerators and denominators when chosen to be from 12 notes as opposed to 11, 13 etc. I hadn't heard about the C vs. A issue, so it's interesting to learn that it's from the monks. I assume the sharp and flat notes are because they're trying to differentiate, as much as possible, the discordant neighboring notes and maybe trying to promote some base mode/scale (like C-major). [0] Measures of Consonances in a Goodness-of-fit Model for Equal-tempered Scales by Aline Honingh