45edo: Difference between revisions
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{{Infobox ET}} | {{Infobox ET}} | ||
{{ | {{ED intro}} | ||
== Theory == | == Theory == | ||
45edo effectively has two major thirds, each almost equally far from just, but as the flat one is slightly closer, it qualifies as a meantone temperament, forming a good approximation to [[2/5-comma meantone]] | 45edo effectively has two approximate major thirds, each almost equally far from [[just]], but as the flat one is slightly closer, it qualifies as a [[meantone]] temperament, forming a good approximation to [[2/5-comma meantone]]. It is a flat-tending system in the [[7-limit]], with 3, 5, and 7 all flat, but the 11 is sharp. | ||
It provides the [[optimal patent val]] for [[flattone]] temperament, 7-limit rank-3 [[avicennmic]] temperament [[tempering out]] [[525/512]], the 11-limit [[calliope]] temperament tempering out [[45/44]] and [[81/80]], and the rank-4 temperament tempering out 45/44. It tempers out 81/80, 3125/3087, 525/512, 875/864 and 45/44. It is also the unique equal temperament tuning whose patent val tempers out both the syntonic comma and the [[ennealimma]]. | |||
45edo tempers out the [[quartisma]] and provides an excellent tuning for the 2.7/3.33 subgroup [[The Quartercache #Direct quartismic|direct quartismic]] temperament, in which it approximates the [[33/32]] quartertone with 2 steps and [[7/6]] with 10 steps. A bit more broadly, it maps the 2.17.25.27.33.63.65 subgroup to great precision; this is the part of the [[17-limit]] shared with [[270edo]]. | |||
Otherwise, it can be treated as a 2.5/3.7/3 subgroup system (borrowing 5/3 from [[15edo]] and 7/3 from [[9edo]]) and is a good tuning for [[gariberttet]], defined by tempering out [[3125/3087]] in this subgroup, approximating 2/5-comma gariberttet. | |||
=== Odd harmonics === | |||
{{Harmonics in equal|45}} | |||
== Intervals == | == Intervals == | ||
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| D | | D | ||
|} | |} | ||
== Notation == | |||
=== Ups and Downs notation === | |||
Spoken as up, sharp, upsharp, etc. Note that up can be respelled as downsharp. | |||
{{sharpness-sharp2a}} | |||
=== Quarter-tone notation === | |||
Since a sharp raises by two steps, [[24edo#Notation|quarter-tone accidentals]] can also be used. | |||
{{sharpness-sharp2}} | |||
=== Sagittal notation === | |||
This notation uses the same sagittal sequence as EDOs [[52edo#Sagittal notation|52]] and [[59edo#Second-best fifth notation|59b]]. | |||
==== Evo flavor ==== | |||
<imagemap> | |||
File:45-EDO_Evo_Sagittal.svg | |||
desc none | |||
rect 80 0 300 50 [[Sagittal_notation]] | |||
rect 300 0 543 80 [https://sagittal.org#periodic-table Periodic table of EDOs with sagittal notation] | |||
rect 20 80 140 106 [[36/35]] | |||
rect 140 80 300 106 [[1053/1024]] | |||
default [[File:45-EDO_Evo_Sagittal.svg]] | |||
</imagemap> | |||
==== Revo flavor ==== | |||
<imagemap> | |||
File:45-EDO_Revo_Sagittal.svg | |||
desc none | |||
rect 80 0 300 50 [[Sagittal_notation]] | |||
rect 300 0 543 80 [https://sagittal.org#periodic-table Periodic table of EDOs with sagittal notation] | |||
rect 20 80 140 106 [[36/35]] | |||
rect 140 80 300 106 [[1053/1024]] | |||
default [[File:45-EDO_Revo_Sagittal.svg]] | |||
</imagemap> | |||
==== Evo-SZ flavor ==== | |||
<imagemap> | |||
File:45-EDO_Evo-SZ_Sagittal.svg | |||
desc none | |||
rect 80 0 300 50 [[Sagittal_notation]] | |||
rect 300 0 511 80 [https://sagittal.org#periodic-table Periodic table of EDOs with sagittal notation] | |||
rect 20 80 140 106 [[36/35]] | |||
rect 140 80 300 106 [[1053/1024]] | |||
default [[File:45-EDO_Evo-SZ_Sagittal.svg]] | |||
</imagemap> | |||
Because it contains no Sagittal symbols, this Evo-SZ Sagittal notation is also a Stein-Zimmerman notation. | |||
In the following diagrams, a sagittal symbol followed by an equals sign (=) means that the following comma is the symbol's [[Sagittal notation#Primary comma|primary comma]] (the comma it ''exactly'' represents in JI), while an approximately equals sign (≈) means it is a secondary comma (a comma it ''approximately'' represents in JI). In both cases the symbol exactly represents the tempered version of the comma in this EDO. | |||
== Regular temperament properties == | == Regular temperament properties == | ||
=== Commas === | === Commas === | ||
This is a partial list of the [[commas]] that | This is a partial list of the [[commas]] that 45et [[tempering out|tempers out]] with its patent [[val]], {{val| 45 71 104 126 143 156 167 }}. | ||
{| class="commatable wikitable center-1 center-2 right-4 center-5" | {| class="commatable wikitable center-1 center-2 right-4 center-5" | ||
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| [[Quartisma]] | | [[Quartisma]] | ||
|} | |} | ||
<references group="note" /> | |||
== Octave stretch and compression == | |||
45edo's approximations of 3/1, 5/1, 7/1, 11/1 and 13/1 and 17/1 are all improved by an [[Octave stretch|stretched-octave]] version of 45edo, such as [[ed6|116ed6]]. The trade-off is a slightly worse 2/1. | |||
The tuning [[equal tuning|183ed17]] may be used for this purpose too, it improves 3/1, 5/1, 7/1, 11/1, 13/1 ''and'' 17/1, but at the cost of a noticeably worse 2/1 than 116ed6. | |||
What follows is a comparison of compressed- and stretched-octave 45edo tunings. | |||
; [[zpi|209zpi]] | |||
* Step size: 26.550{{c}}, octave size: 1194.8{{c}} | |||
Compressing the octave of 45edo by around 5{{c}} results in improved primes 5 and 7, but worse primes 2, 3, 11 and 13. This approximates all harmonics up to 16 within 11.1{{c}}. The tuning 209zpi does this. | |||
{{Harmonics in cet|26.550|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 209zpi}} | |||
{{Harmonics in cet|26.550|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 209zpi (continued)}} | |||
; 45edo | |||
* Step size: 26.667{{c}}, octave size: 1200.0{{c}} | |||
Pure-octaves 45edo approximates all harmonics up to 16 within 13.0{{c}}. | |||
{{Harmonics in equal|45|2|1|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 45edo}} | |||
{{Harmonics in equal|45|2|1|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 45edo (continued)}} | |||
; [[WE|45et, 13-limit WE tuning]] | |||
* Step size: 26.695{{c}}, octave size: 1201.3{{c}} | |||
Stretching the octave of 45edo by around 1{{c}} results in improved primes 3, 5, 7 and 13, but worse primes 2 and 11. This approximates all harmonics up to 16 within 13.2{{c}}. Its 13-limit WE tuning and 13-limit [[TE]] tuning both do this. | |||
{{Harmonics in cet|26.695|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 45et, 13-limit WE tuning}} | |||
{{Harmonics in cet|26.695|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 45et, 13-limit WE tuning (continued)}} | |||
; [[ed12|161ed12]] | |||
* Step size: Octave size: 1202.4{{c}} | |||
Stretching the octave of 45edo by around 2.5{{c}} results in improved primes 3, 5, 7 and 13, but worse primes 2 and 11. This approximates all harmonics up to 16 within 12.2{{c}}. The tuning 161ed12 does this. | |||
{{Harmonics in equal|161|12|1|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 161ed12}} | |||
{{Harmonics in equal|161|12|1|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 161ed12 (continued)}} | |||
; [[ed6|116ed6]] | |||
* Step size: Octave size: 1203.3{{c}} | |||
Stretching the octave of 45edo by around 3{{c}} results in improved primes 3, 5, 7, 11 and 13, but a worse prime 2. This approximates all harmonics up to 16 within 13.4{{c}}. The tuning 116ed6 does this. So does [[ed7|126ed7]] whose octave is identical within 0.1{{c}}. | |||
{{Harmonics in equal|116|6|1|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 116ed6}} | |||
{{Harmonics in equal|116|6|1|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 116ed6 (continued)}} | |||
; [[WE|45et, 7-limit WE tuning]] | |||
* Step size: 26.745{{c}}, octave size: 1203.5{{c}} | |||
Stretching the octave of 45edo by around 3.5{{c}} results in improved primes 3, 5, 7, 11 and 13, but a worse prime 2. This approximates all harmonics up to 16 within 12.6{{c}}. Its 7-limit WE tuning and 7-limit [[TE]] tuning both do this. | |||
{{Harmonics in cet|26.745|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 45et, 7-limit WE tuning}} | |||
{{Harmonics in cet|26.745|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 45et, 7-limit WE tuning (continued)}} | |||
; [[zpi|207zpi]] | |||
* Step size: 26.762{{c}}, octave size: 1204.3{{c}} | |||
Stretching the octave of 45edo by around 4{{c}} results in improved primes 3, 5, 7, 11 and 13, but a worse prime 2. This approximates all harmonics up to 16 within 12.9{{c}}. The tuning 207zpi does this. | |||
{{Harmonics in cet|26.762|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 207zpi}} | |||
{{Harmonics in cet|26.762|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 207zpi (continued)}} | |||
; [[71edt]] | |||
* Step size: 26.788{{c}}, octave size: 1205.5{{c}} | |||
Stretching the octave of 45edo by around 5.5{{c}} results in improved primes 3, 5, 7, 11 and 13, but a worse prime 2. This approximates all harmonics up to 16 within 11.9{{c}}. The tuning 71edt does this. So do the tunings [[ed5|104ed5]] and [[equal tuning|155ed11]] whose octave is identical within 0.3{{c}}. | |||
{{Harmonics in equal|71|3|1|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 71edt}} | |||
{{Harmonics in equal|71|3|1|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 71edt (continued)}} | |||
; [[equal tuning|183ed17]] | |||
* Octave size: 1206.1{{c}} | |||
Stretching the octave of 45edo by around 6{{c}} results in improved primes 3, 5, 7, 11, 13 and 17, but a worse prime 2. This approximates all harmonics up to 16 within 13.3{{c}}. The tuning 183ed17 does this. | |||
{{Harmonics in equal|183|17|1|intervals=integer|columns=11|collapsed=true|title=Approximation of harmonics in 183ed17}} | |||
{{Harmonics in equal|183|17|1|intervals=integer|columns=12|start=12|collapsed=true|title=Approximation of harmonics in 183ed17 (continued)}} | |||
== Instruments == | == Instruments == | ||
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== Music == | == Music == | ||
; [[Bryan Deister]] | |||
* [https://www.youtube.com/shorts/33tKBiWZvXM ''(short clip) Fantasy in 45edo''] (2025) | |||
; [[JUMBLE]] | ; [[JUMBLE]] | ||
* [https://www.youtube.com/watch?v=tbc_OxHp-ec ''Fishbowl''] (2023) | * [https://www.youtube.com/watch?v=tbc_OxHp-ec ''Fishbowl''] (2023) | ||
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* [https://www.youtube.com/watch?v=Kd4t_iKiKMA ''Fallen Angel''] (2024) | * [https://www.youtube.com/watch?v=Kd4t_iKiKMA ''Fallen Angel''] (2024) | ||
* [https://www.youtube.com/watch?v=DPztb8W6ykY ''Solar Guardian''] (2024) | * [https://www.youtube.com/watch?v=DPztb8W6ykY ''Solar Guardian''] (2024) | ||
[[Category:Equal divisions of the octave|##]] <!-- 2-digit number --> | [[Category:Equal divisions of the octave|##]] <!-- 2-digit number --> |