Fractional sharp notation
The letter notation is a notation scheme developed by CompactStar for just intonation up to the 31-limit, as well as having some use for regular temperaments. It is 3-limit notation with the letters H-Z used as accidentals for higher prime limits (starting from H to avoid conflict with note names). These o are fairly easy to memorize as they go in alphabetical order as the prime limit increases.
Accidentals
| Prime limit | Letter | Ratio | Letter | Ratio |
|---|---|---|---|---|
| 5 | H | 81/80 | I | 80/81 |
| 7 | J | 64/63 | K | 63/64 |
| 11 | L | 33/32 | M | 32/33 |
| 13 | N | 1053/1024 | O | 1024/1053 |
| 17 | P | 4131/4096 | Q | 4096/4131 |
| 19 | R | 513/512 | S | 512/513 |
| 23 | T | 736/729 | U | 729/736 |
| 29 | V | 261/256 | W | 256/261 |
| 31 | X | 32/31 | Y | 31/32 |