240edo: Difference between revisions

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{{Infobox ET}}
{{Infobox ET}}
{{EDO intro|240}}
{{ED intro}}
==Theory==
240edo is a [[dual-fifth system]]. Nonetheless, it is [[consistent]] in the 5-limit and notably provides the [[optimal patent val]] for the [[compton]] temperament, the rank-2 temperament associated with the [[Pythagorean comma]]. Alternate mapping for 3/2 is the 705-cent sharp fifth inherited from [[80edo]].


Although no longer consistent to to the higher limits, 240edo's patent val tempers out the [[225/224]] in the 7-limit, supporting [[marvel]] and [[spectacle]] temperaments with harmonics 3, 5, 7 having less than two cents of error. Retuning 5-limit scales to 240edo is a simple way to to make them function as 7-limit scales while retaining very accurate tuning.  
== Theory ==
240edo notably provides the [[optimal patent val]] for the 5-limit [[compton]] temperament, the rank-2 temperament associated with the [[Pythagorean comma]]. However, it is only [[consistent]] in the [[5-odd-limit]]. Its mapping for [[harmonic]] [[3/1|3]] is not well approximated, meaning it is a [[dual-fifth system]]; its alternative mapping for 3/2 is the 705{{c}} sharp fifth inherited from [[80edo]].  


From a regular temperament theory perspective in the 7-limit, 240edo is similar to [[197edo]]. The main difference is that 197edo, despite a flatter third, gives generally better results and may be preferred, whitherfore a compromise between good results and an accurate 5 may be worked out by means of retuning 5-limit scales to the 197 & 240 temperament, whhich has a comma basis {225/224, {{monzo|-49 19 -10 15}}} in the 7-limit.
Although no longer consistent to the higher limits, 240edo's [[patent val]] [[tempering out|tempers out]] the [[225/224]] in the 7-limit, [[support]]ing [[marvel]] with harmonics 3, [[5/1|5]], [[7/1|7]] having less than two cents of error. Retuning 5-limit scales to 240edo is a simple way to to make them function as 7-limit scales while retaining very accurate tuning.  


For higher limits, 240edo tempers out [[243/242]] in the 11-limit, [[351/350]] in the 13-limit, and [[375/374]] in the 17-limit, and adding these to the mix converts marvel temperament into [[spectacle]] temperament. This is still a planar temperament, but more complex as two unidecimal neutral thirds of 11/9 make up a fifth (which is in fact the same fifth as that of 12edo, and the 11/9 is the 350 cent interval often employed in 24edo versions of Arabic music.) Musical intervals are therefore generated by octaves, major thirds, and neutral thirds in spectacle. 3/2 is equated with two 11/9 as a corollary of 243/242 being tempered out, 7/4 is equated with a stack of four 11/9s and two 5/4s, 11/8 is equated with a stack of five 11/9s, 13/8 is equated with a stack of two 18/11s and four 5/4s, and 17/16 is equated with three 18/11s and three 5/4s. Every harmonic is reached with help of other intervals at most with three 5/4s.
240edo is similar to [[197edo]] in terms of intonation in the 7-limit. The main difference is that 197edo, despite a flatter third, gives generally better results and may be preferred, whitherfore a compromise between good results and an accurate 5 may be worked out by means of retuning 5-limit scales to the {{nowrap| 43 & 197 }} temperament, which has a comma basis {225/224, {{monzo| -49 19 -10 15 }}} in the 7-limit.
 
For higher limits, 240edo tempers out [[243/242]] in the 11-limit, [[351/350]] in the 13-limit, and [[375/374]] in the 17-limit, and adding these to the mix converts marvel temperament into [[spectacle]] temperament. This is still a [[rank-3 temperament]], but more complex as two undecimal neutral thirds of [[11/9]] make up a fifth (which is in fact the same fifth as that of 12edo, and the 11/9 is the 350-cent interval often employed in [[24edo]] versions of [[Arabic, Turkish, Persian music|Arabic music]].)
 
=== Odd harmonics ===
{{Harmonics in equal|240}}


=== Subsets and supersets ===
=== Subsets and supersets ===
240edo is the 12th [[highly composite EDO]], with subset EDOs 1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, 120.  
240edo is the 12th [[highly composite edo]], with subset edos {{EDOs| 2, 3, 4, 5, 6, 8, 10, 12, 15, 16, 20, 24, 30, 40, 48, 60, 80, 120 }}. In addition, as every fifth step of [[1200edo]], it is the largest highly composite edo expressible in integer cents.


In addition, as every fifth step of [[1200edo]], it is the largest highly composite EDO compatible with cents.
== Interval table ==
See [[Table of 240edo intervals]].  


=== Odd harmonics ===
== Regular temperament properties ==
{{Harmonics in equal|240}}
{| class="wikitable center-4 center-5 center-6"
|-
! rowspan="2" | [[Subgroup]]
! rowspan="2" | [[Comma list]]
! rowspan="2" | [[Mapping]]
! rowspan="2" | Optimal<br>8ve stretch (¢)
! colspan="2" | Tuning error
|-
! [[TE error|Absolute]] (¢)
! [[TE simple badness|Relative]] (%)
|-
| 2.3.5
| 531441/524288, {{monzo| -29 -11 20 }}
| {{Mapping| 240 380 557 }}
| 0.5998
| 0.5044
| 10.09
|}


==Scales==
=== Rank-2 temperaments ===
{| class="wikitable center-all left-5"
|+ style="font-size: 105%;" | Table of rank-2 temperaments by generator
|-
! Periods<br>per 8ve
! Generator*
! Cents*
! Associated<br>ratio*
! Temperaments
|-
| 1
| 7\240
| 35.00
| 45/44
| [[Gammy]]
|-
| 1
| 101\240
| 505.00
| 104976/78125
| [[Countermeantone]]
|-
| 12
| 77\240<br>(3\240)
| 385.00<br>(15.00)
| 5/4<br>(81/80)
| [[Compton]]
|}
<nowiki/>* [[Normal forms #Equave-reduced-generator form|Octave-reduced form]], reduced to the first half-octave, and [[normal forms #Minimal-generator form|minimal form]] in parentheses if distinct


== Scales ==
; Scales derived from marvel and spectacle temperaments
; Scales derived from marvel and spectacle temperaments
* 23 17 23 14 23 17 23 23 14 26 14 23 - Ellis's Duodene genus [33355] retuned to 240edo
* 23 17 23 14 23 17 23 23 14 26 14 23 – [[Alexander Ellis|Ellis]]'s [[Duodene]] genus [33355] retuned to 240edo
* 23 17 14 23 23 17 23 23 14 17 23 23 - Carl Lumma's scale
* 23 17 14 23 23 17 23 23 14 17 23 23 – [[Carl Lumma]]'s scale
* 14 9 14 17 23 23 23 17 14 9 14 23 17 23 - Pum[14] scale
* 14 9 14 17 23 23 23 17 14 9 14 23 17 23 Pum[14] scale
* 16 10 7 7 16 7 7 16 7 10 7 16 7 7 16 7 7 10 16 7 7 16 7 - Ellis duodene union 11/9 times the duodene
* 16 10 7 7 16 7 7 16 7 10 7 16 7 7 16 7 7 10 16 7 7 16 7 Ellis duodene union [[11/9]] times the duodene
 
=== Other scales ===
* 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 – [[Compton]][24]
* 23 31 80 23 83 – [[Indonesian|Balinese]] pentatonic [[pelog]] scale; [[Tolgahan Çoğulu]]'s tuning


; Other scales
== Instruments ==
A [[Lumatone mapping for 240edo]] is now available.


* 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 17 3 - Compton[24]
== Music ==
* 23 31 80 23 83 - [[Indonesian|Balinese]] pentatonic [[pelog]] scale; [[Tolgahan Çoğulu]]'s tuning
; [[Chris Charles]] (via [https://www.youtube.com/@microtonalguitar Microtonal Guitar - Tolgahan Çoğulu])
* [https://www.youtube.com/watch?v=6GoGlj5IyZc ''Balinese Gamelan Music on Microtonal Guitar - Chris Charles''] (2017) (Uses a 5-tone subset of 240edo for all three pieces performed in the recording—as explained in the video description: "''The scale we used in the piece: Pelog Selisir: D, Eb +30 F -15 A -30 Bb -15''".)


==Music==
; [[Bryan Deister]]
The video ''[https://www.youtube.com/watch?v=6GoGlj5IyZc Balinese Gamelan Music on Microtonal Guitar - Chris Charles]'' on the YouTube channel ''[https://www.youtube.com/@microtonalguitar Microtonal Guitar - Tolgahan Çoğulu]'' uses a 5-tone subset of 240edo for all three pieces performed in the recording. As explained in the video description: "''The scale we used in the piece: Pelog Selisir: D, Eb +30 F -15 A -30 Bb -15''".
* [https://www.youtube.com/shorts/Nu-xBrsd8_o ''microtonal improvisation in 240edo''] (2025)


==Links==
== Trivia ==
[[Shaahin_Mohajeri|Shaahin Mohajeri]], an [[Arabic, Turkish, Persian music|Iranian]] Tombak player and composer, calls his personal [https://sites.google.com/site/240edo/ Google site] "240edo", where he makes the point that five cents is a size close to the [[Just-noticeable_difference|just noticeable difference]] between pitches.
[[Shaahin Mohajeri]], an [[Arabic, Turkish, Persian music|Iranian]] Tombak player and composer, calls his personal [https://sites.google.com/site/240edo/ Google site] "240edo", where he makes the point that five cents is a size close to the [[just-noticeable difference]] between pitches.


[[Category:Equal divisions of the octave|###]] <!-- 3-digit number -->
[[Category:Compton]]
[[Category:Compton]]
[[Category:Marvel]]
[[Category:Marvel]]