Lower bound Symbol Ratio Name Most common semitone fraction ------------- ------ ----------- ---- ----------------------------- -3.99999999 1/1 0 3.99999999 4131/4096 17C 1/12 9.090909101 41553/40960 5:19C 1/10 11.99999999 81/80 5C 1/6 16.66666668 3645/3584 5:7C 1/5 (5:7C is and not a valid secondary comma for ) 22.22222223 2048/2025 25C 1/4 (25C is and not a valid secondary comma for ) 28.57142856 64/63 7C 1/3 33.33333334 55/54 55C 3/8 38.88888888 46/45 5:23S 2/5 42.85714285 36/35 35M 4/9 48.00000001 33/32 11M 1/2 51.99999999 8505/8192 35L 5/8 57.14285715
To my horror, I find that Trojan is using secondary commas that are no longer valid (if they ever were), as you can see here: http://sagittal.org/SagittalJI.gif
Here are some spreadsheets I used in designing the Trojan notation.