420edo: Difference between revisions

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{{Infobox ET}}
{{Infobox ET}}
{{EDO intro|420}}
{{ED intro}}


== Theory ==
== Theory ==
420edo is [[enfactoring|enfactored]] in the 7-limit, with the same tuning of [[3/1|3]], [[5/1|5]], and [[7/1|7]] as [[140edo]]. The [[13/1|13th]] [[harmonic]] is also present in 140edo, and ultimately derives from [[10edo]]. The [[29/1|29th harmonic]], while having significantly drifted in terms of [[relative interval error]], has retained its step position from [[7edo]]. In addition, in the 29-limit, only 11 and 17 have step correspondences coprime with 420. This means that all other approximations are preserved from smaller edos, thus enabling edo mergers and mashups.
420edo is [[enfactoring|enfactored]] in the 7-limit, with the same tuning of [[harmonic]]s [[3/1|3]], [[5/1|5]], and [[7/1|7]] as [[140edo]]. The [[13/1|13th harmonic]] is also present in 140edo, and ultimately derives from [[10edo]]. The [[29/1|29th harmonic]], while having significantly drifted in terms of [[relative interval error]], has retained its step position from [[7edo]]. In addition, in the 29-limit, only the harmonics 11 and 17 have step numbers coprime with 420. This means that all other approximations are preserved from smaller edos, thus enabling edo mergers and mashups.


420edo is good at the 2.5.7.11.13.19.23 [[subgroup]], and has a great potential as a near-just xenharmonic system. It also works satisfactorily with the 29-limit as a whole, though in[[consistent]]. In the 11-limit, it notably tempers out [[4000/3993]], and in the 13-limit, [[10648/10647]].  
420edo is good at the 2.5.7.11.13.19.23 [[subgroup]], and has a great potential as a near-just xenharmonic system. It also works satisfactorily with the 29-limit as a whole, though in[[consistent]]. In the 11-limit, it notably tempers out [[4000/3993]], and in the 13-limit, [[10648/10647]].  
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=== Subsets and supersets ===
=== Subsets and supersets ===
420 is a largely composite number, being divisible by {{EDOs| 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 70, 84, 105, 140, and 210 }}. For this reason 420edo is rich in modulation circles.
420 is a largely composite number, its nontrivial subset edos being {{EDOs| 2, 3, 4, 5, 6, 7, 10, 12, 14, 15, 20, 21, 28, 30, 35, 42, 60, 70, 84, 105, 140, and 210 }}. For this reason 420edo is rich in modulation circles.


== Trivia ==
== Trivia ==
The approximation to the third harmonic, which derives from 70edo, constitutes 666 steps of 420edo. Nice.
The approximation to the third harmonic, which derives from 70edo, constitutes 666 steps of 420edo.


== Regular temperament properties ==
== Regular temperament properties ==
{| class="wikitable center-4 center-5 center-6"
{| class="wikitable center-4 center-5 center-6"
|-
! rowspan="2" | [[Subgroup]]
! rowspan="2" | [[Subgroup]]
! rowspan="2" | [[Comma list|Comma List]]
! rowspan="2" | [[Comma list|Comma List]]
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| 2.3.5.7.11
| 2.3.5.7.11
| 2401/2400, 4000/3993, 5120/5103, 15625/15552
| 2401/2400, 4000/3993, 5120/5103, 15625/15552
| [{{val| 420 666 975 1179 1453 }}]
| {{mapping| 420 666 975 1179 1453 }}
| -0.051
| −0.051
| 0.278
| 0.278
| 9.74
| 9.74
|-
|- style="border-top: double;"
|style="border-top: double;" |2.5.7.11.13.19.23
| 2.5.7.11.13.19.23
|style="border-top: double;" |875/874, 5635/5632, 10241/10240, 12103/12100, 11875/11858, 10985/10976
| 875/874, 5635/5632, 10241/10240, 12103/12100, 11875/11858, 10985/10976
|style="border-top: double;" |[{{val|420 975 1179 1453 1554 1784 1900}}]
| {{mapping| 420 975 1179 1453 1554 1784 1900 }}
|style="border-top: double;" |0.069
| +0.069
|style="border-top: double;" |0.104
| 0.104
|style="border-top: double;" |3.62
| 3.62
|}
|}


== Music ==
== Music ==
; [[Mandrake]]
; [[Mandrake]]
* ''[https://www.youtube.com/watch?v=X1deLLCJD64 Follow In Is]'' – a superset of [[12edo]], [[5edo]], and [[7edo]], least common multiple of which is 420edo.
* [https://youtu.be/X1deLLCJD64?si=baHHYZQV9VFMaJZs ''Follow In Is''] (2022) – a superset of [[12edo]], [[5edo]], and [[7edo]], least common multiple of which is 420edo.
 
[[Category:Listen]]