45edo: Difference between revisions

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{{Infobox ET}}
{{Infobox ET}}
{{EDO intro|45}}
{{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]]. It is the [[optimal patent val]] for [[flattone]] temperament, the 525/512 [[planar]] 7-limit [[Avicennmic_temperaments|avicennmic]] temperament, the 11-limit [[calliope]] temperament tempering out [[45/44]] and [[81/80]], and the rank four temperament tempering out 45/44. It tempers out 81/80, 3125/3087, 525/512, 875/864 and 45/44. It is a flat-tending system in the [[7-limit]], with 3, 5 and 7 all flat, but the 11 is sharp.
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.  


45edo tempers out the [[quartisma]] and provides an excellent tuning for the 2.33/32.7/6 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. It is also the unique equal temperament tuning that [[tempers out]] both the [[syntonic comma]] and the [[ennealimma]].
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 ===
=== Odd harmonics ===
{{harmonics in equal|45}}
{{Harmonics in equal|45}}


=== Octave stretch ===
=== Octave stretch ===
45edo’s approximations of 3/1, 5/1, 7/1, 11/1, 13/1 and 17/1 are all improved by [[Gallery of arithmetic pitch sequences#APS of farabs|APS3.21farab]], a [[Octave stretch|stretched-octave]] version of 45edo. The trade-off is a slightly worse 2/1.
45edo's approximations of 3/1, 5/1, 7/1, 11/1, 13/1 and 17/1 are all improved by [[equal tuning|13ed11/9]], a [[Octave stretch|stretched-octave]] version of 45edo. The trade-off is a slightly worse 2/1.


The tuning [[126ed7]] may be used for this purpose too, it improves 3/1, 5/1, 7/1, 11/1 and 13/1, at the cost of a slightly worse 2/1.
The tuning [[126ed7]] may be used for this purpose too, it improves 3/1, 5/1, 7/1, 11/1 and 13/1, at the cost of a slightly worse 2/1.
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== Notation ==
== Notation ==


===Sagittal notation===
=== Ups and Downs 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.
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}}


This notation uses the same sagittal sequence as EDOs [[52edo#Sagittal notation|52]] and [[59edo#Sagittal notation|59b]].
=== Sagittal notation ===
====Evo flavor====
This notation uses the same sagittal sequence as EDOs [[52edo#Sagittal notation|52]] and [[59edo#Second-best fifth notation|59b]].


==== Evo flavor ====
<imagemap>
<imagemap>
File:45-EDO_Evo_Sagittal.svg
File:45-EDO_Evo_Sagittal.svg
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</imagemap>
</imagemap>


====Revo flavor====
==== Revo flavor ====
 
<imagemap>
<imagemap>
File:45-EDO_Revo_Sagittal.svg
File:45-EDO_Revo_Sagittal.svg
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</imagemap>
</imagemap>


====Evo-SZ flavor====
==== Evo-SZ flavor ====
 
<imagemap>
<imagemap>
File:45-EDO_Evo-SZ_Sagittal.svg
File:45-EDO_Evo-SZ_Sagittal.svg
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Because it contains no Sagittal symbols, this Evo-SZ Sagittal notation is also a Stein-Zimmerman notation.
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 45edo [[tempers out]] with its patent [[val]], {{val| 45 71 104 126 143 156 167 }}.
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" />


== 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)
== Notes ==
<references group="note" />


[[Category:Equal divisions of the octave|##]] <!-- 2-digit number -->
[[Category:Equal divisions of the octave|##]] <!-- 2-digit number -->