Last time I said a bit about ‘just intonation’: that is, tuning where the most important notes have frequency ratios that are simple fractions. I focused on the historically important case of ‘5-limit tuning’, where the frequency ratios are products of powers of primes ≤ 5.
This is a companion discussion topic for the original entry at https://johncarlosbaez.wordpress.com/2023/11/09/just-intonation-part-3/