99edo: Difference between revisions

From Xenharmonic Reference
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{{Harmonics in ED|99}}
{{Harmonics in ED|99}}
=== 7-prime-limited odd-limit analysis ===
=== 7-prime-limited odd-limit analysis ===
99edo is ''distinctly'' consistent and monotone (i.e. relative sizes of any two intervals are never conflated ''or'' reversed) in the following 7-prime-limited odd-limits:
99edo is ''distinctly'' consistent and monotone (i.e. relative sizes of any two intervals are never conflated ''or'' reversed) up to the 7-prime-limited 45-odd-limit, unlike all previous edos:
* 7-OL: 8/7; 7/6; 6/5; 5/4; 4/3; 7/5; 10/7; 3/2; 8/5; 5/3; 12/7; 7/4; 2/1;
 
* 9-OL: add 10/9; 9/8; 9/7; 14/9; 16/9; 9/5;
36/35; 28/27; 16/15; 15/14; 27/25; 35/32; 10/9; 28/25; 9/8; 8/7; 7/6; 32/27; 25/21; 6/5; 56/45; 5/4; 32/25; 9/7; 35/27; 21/16; 4/3; 27/20; 48/35; 7/5; 45/32; 64/45; 10/7; 35/24; 40/27; 3/2; 32/21; 54/35; 14/9; 25/16; 8/5; 45/28; 5/3; 42/25; 27/16; 12/7; 7/4; 16/9; 25/14; 9/5; 64/35; 50/27; 28/15; 15/8; 27/14; 35/18; 2/1
* 7-PL 15-OL: add 16/15; 15/14: 28/15; 15/8;
 
* 7-PL 21-OL: add 21/16; 32/21;
* 7-PL 25-OL: add 28/25; 25/21; 32/25; 25/16; 42/25; 25/14;
* 7-PL 27-OL: add 28/27; 27/25; 32/27; 27/20; 40/27; 27/16; 50/27; 27/14;
* 7-PL 35-OL: add 36/35; 35/32; 35/27; 48/35; 35/24; 54/35; 64/35; 35/18;
* 7-PL 45-OL: add 56/45; 45/32; 64/45; 45/28;
The 7-prime-limited 49-odd-limit is where non-distinctness first shows up: namely, T49/48 = T50/49 (this is characteristic of all ennealimmal tunings). However 99edo remains monotone and consistent in these odd-limits: (todo)
The 7-prime-limited 49-odd-limit is where non-distinctness first shows up: namely, T49/48 = T50/49 (this is characteristic of all ennealimmal tunings). However 99edo remains monotone and consistent in these odd-limits: (todo)



Revision as of 15:21, 8 April 2026

99edo is an equal tuning with steps of size 12.12... cents. It is arguably the edo below 100 that models 7-limit just intonation the most faithfully.

Theory

Prime approximations

Approximation of prime harmonics in 99edo
Harmonic 2 3 5 7 11 13 17 19 23 29 31
Error Absolute (¢) 0.0 +1.1 +1.6 +0.9 -5.9 -4.2 +4.1 +5.5 +2.0 +0.7 -5.6
Relative (%) 0.0 +8.9 +12.9 +7.2 -48.4 -34.4 +34.1 +45.5 +16.7 +6.0 -46.5
Steps

(reduced)

99

(0)

157

(58)

230

(32)

278

(80)

342

(45)

366

(69)

405

(9)

421

(25)

448

(52)

481

(85)

490

(94)

7-prime-limited odd-limit analysis

99edo is distinctly consistent and monotone (i.e. relative sizes of any two intervals are never conflated or reversed) up to the 7-prime-limited 45-odd-limit, unlike all previous edos:

36/35; 28/27; 16/15; 15/14; 27/25; 35/32; 10/9; 28/25; 9/8; 8/7; 7/6; 32/27; 25/21; 6/5; 56/45; 5/4; 32/25; 9/7; 35/27; 21/16; 4/3; 27/20; 48/35; 7/5; 45/32; 64/45; 10/7; 35/24; 40/27; 3/2; 32/21; 54/35; 14/9; 25/16; 8/5; 45/28; 5/3; 42/25; 27/16; 12/7; 7/4; 16/9; 25/14; 9/5; 64/35; 50/27; 28/15; 15/8; 27/14; 35/18; 2/1

The 7-prime-limited 49-odd-limit is where non-distinctness first shows up: namely, T49/48 = T50/49 (this is characteristic of all ennealimmal tunings). However 99edo remains monotone and consistent in these odd-limits: (todo)

Edostep interpretations

1\99 represents the following 7-limit ratios:

  • 126/125
  • 225/224
  • 245/243
  • 1029/1024
  • 1728/1715
  • 2048/2025
  • 4000/3969

2\99 represents the following 7-limit ratios:

  • 64/63
  • 81/80

3\99 represents the following 7-limit ratios:

  • 49/48
  • 50/49
  • 128/125

Temperaments

99edo notably supports

Derivation

Todo: Derive 99edo from

  • Didacus
  • Aberschismic
  • Don't temper out 81/80, 64/63, or 128/125
  • Ennealimmal


ViewTalkEditEqual temperaments
EDOs
Macrotonal 57891011
12-23 121314151617181920212223
24-35 242526272931323435
36-47 36373940414344454647
48-59 4850515354565758
60-71 60636465676870
72-83 72778081
84-95 848789909394
Large EDOs 99104106111118130140152159171217224239270306311612665
Nonoctave equal temperaments
Tritave 4913172639
Fifth 891120
Other