187edo: Difference between revisions

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{{ED intro}}
{{ED intro}}


This edo is a bit of a chimera. It has a [[3/2|fifth]] which is 2.9{{c}} flat and a [[5/4|classical major third]] 1.3 cents flat, but the [[7/1|7]], [[11/1|11]] and [[13/1|13]] are more accurate. The equal temperament [[tempering out|tempers out]] 78732/78125 ([[sensipent comma]]) in the 5-limit and [[225/224]] in the 7-limit, providing the [[optimal patent val]] for [[sensei]] which tempers out both. In the 11-limit it tempers out [[441/440]], 1375/1372 and [[4000/3993]] and in the 13-limit [[351/350]], [[625/624]], [[1188/1183]], [[1716/1715]] and [[2200/2197]].
== Theory ==
This edo is a bit of a chimera. It has a [[3/2|fifth]] which is 2.9{{c}} flat and a [[5/4|classical major third]] 1.3 cents flat, but the [[7/1|7]], [[11/1|11]] and [[13/1|13]] are more accurate.  
 
Using the [[patent val]], the equal temperament [[tempering out|tempers out]] 78732/78125 ([[sensipent comma]]) in the [[5-limit]] and [[225/224]] in the [[7-limit]], providing the [[optimal patent val]] for [[sensei]], which tempers out both. In the [[11-limit]] it tempers out [[441/440]], [[1375/1372]] and [[4000/3993]], and in the [[13-limit]] [[351/350]], [[625/624]], [[1188/1183]], [[1716/1715]] and [[2200/2197]].


=== Odd harmonics ===
=== Odd harmonics ===
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=== Subsets and supersets ===
=== Subsets and supersets ===
Since 187 factors into {{factorization|187}}, 187edo contains [[11edo]] and [[17edo]] as its subsets.
Since 187 factors into {{nowrap| 11 × 17 }}, 187edo contains [[11edo]] and [[17edo]] as its subsets.


=== Music ===
== Music ==
* ''[https://www.youtube.com/watch?v=vrFU2J25G1Y Pillow(33) (187edo lullaby)]'' by [[JUMBLE]] (Dec 2024, uses MOS [[22L 11s]])
; [[JUMBLE]]
* [https://www.youtube.com/watch?v=vrFU2J25G1Y ''Pillow(33)''] (2024) – a 187edo lullaby, using the [[22L 11s]] [[mos]]

Latest revision as of 10:00, 17 June 2026

← 186edo 187edo 188edo →
Prime factorization 11 × 17
Step size 6.41711 ¢ 
Fifth 109\187 (699.465 ¢)
Semitones (A1:m2) 15:16 (96.26 ¢ : 102.7 ¢)
Dual sharp fifth 110\187 (705.882 ¢) (→ 10\17)
Dual flat fifth 109\187 (699.465 ¢)
Dual major 2nd 32\187 (205.348 ¢)
Consistency limit 7
Distinct consistency limit 7

187 equal divisions of the octave (abbreviated 187edo or 187ed2), also called 187-tone equal temperament (187tet) or 187 equal temperament (187et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 187 equal parts of about 6.42 ¢ each. Each step represents a frequency ratio of 21/187, or the 187th root of 2.

Theory

This edo is a bit of a chimera. It has a fifth which is 2.9 ¢ flat and a classical major third 1.3 cents flat, but the 7, 11 and 13 are more accurate.

Using the patent val, the equal temperament tempers out 78732/78125 (sensipent comma) in the 5-limit and 225/224 in the 7-limit, providing the optimal patent val for sensei, which tempers out both. In the 11-limit it tempers out 441/440, 1375/1372 and 4000/3993, and in the 13-limit 351/350, 625/624, 1188/1183, 1716/1715 and 2200/2197.

Odd harmonics

Approximation of odd harmonics in 187edo
Harmonic 3 5 7 9 11 13 15 17 19 21 23
Error Absolute (¢) -2.49 -1.29 +0.16 +1.44 +0.55 +0.11 +2.64 -2.28 -2.33 -2.33 +0.60
Relative (%) -38.8 -20.1 +2.5 +22.4 +8.6 +1.8 +41.1 -35.6 -36.2 -36.3 +9.4
Steps
(reduced)
296
(109)
434
(60)
525
(151)
593
(32)
647
(86)
692
(131)
731
(170)
764
(16)
794
(46)
821
(73)
846
(98)

Subsets and supersets

Since 187 factors into 11 × 17, 187edo contains 11edo and 17edo as its subsets.

Music

JUMBLE