1789edo: Difference between revisions

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1789edo can be adapted for use with the 2.5.11.13.29.31.47.59.61 subgroup.  
1789edo can be adapted for use with the 2.5.11.13.29.31.47.59.61 subgroup.  


Since 1789edo contains the 2.5 subgroup, it can be used for the finite decimal temperament - that is, where all the interval targets in just intonation are expressed as terminating decimals. For example, [[5/4]], [[25/16]], [[128/125]], [[32/25]], 625/512, etc. This rings particularly true for the French attempts to decimalize a lot more things than we are used to today. This property of 1789edo is amplified by poor approximation of 3 and 7, allowing for cognitive separation of the intervals (or whatever is left of it at such small step size).
=== Jacobin temperament ===
The "proper" Jacobin temperament in 1789edo, the maximum evenness scale that uses 822 as a generator, contains only 37 notes. The step sizes are 48 and 49, making them indistinguishable to human ear at this scale. This can be fixed by using divisors of 822 as a generaator, for example 137\1789 "6th root of 11/8" temperament having 222 notes. In addition, this can be re-interpreted by using 13/10 as a generator instead which produces a more vibrant 1205 out of 1789, and partitioning the resulting 13/5s in three around the octave. Addition of 29 and 31 harmonic intervals may also be suitable to spice up an otherwise monotonous scale.


In addition, since the 5/4 of 1789edo is on the 576th step, a highly divisible number, 1789edo can replicate a lot of [[Ed5/4]] temperaments - more exactly those which are divisors of 576, and that includes all from [[2ed5/4]] to [[9ed5/4]], skipping [[7ed5/4]].  
Using the maximal evenness method of finding rank two temperaments, we get a 37 & 1789 temperament.


The "proper" Jacobin temperament in 1789edo, the maximum evenness scale that uses 822 as a generator, contains only 37 notes. The step sizes are 48 and 49, making them indistinguishable to human ear at this scale. This can be fixed by using divisors of 822 as a generaator, for example 137\1789 "6th root of 11/8" temperament having 222 notes. In addition, this can be re-interpreted by using 13/10 as a generator instead which produces a more vibrant 1205 out of 1789, and partitioning the resulting 13/5s in three around the octave. Addition of 29 and 31 harmonic intervals may also be suitable to spice up an otherwise monotonous scale.
=== Decimal temperament ===
Since 1789edo contains the 2.5 subgroup, it can be used for the finite decimal temperament - that is, where all the interval targets in just intonation are expressed as terminating decimals. For example, [[5/4]], [[25/16]], [[128/125]], [[32/25]], 625/512, etc. This rings particularly true for the French attempts to decimalize a lot more things than we are used to today. This property of 1789edo is amplified by poor approximation of 3 and 7, allowing for cognitive separation of the intervals (or whatever is left of it at such small step size).
 
Using the maximal evenness method of finding rank two temperaments, we get a 1524 & 1789 temperament.
 
=== Other ===
For its elaborate xenharmonicity, 1789edo has an essentially perfect [[9/8]], a very common interval. The associated comma is [5671 -3578⟩. This is a direct consequence of 1789edo being a [[dual-fifth system]]. 1046th and 1047th steps aren't associated with JI intervals by themselves, but satisfy 3 × 3II = 9, which represents 9/1, and therefore when octave reduced this leads to 9/8.  


For its elaborate xenharmonicity, 1789edo has an essentially perfect [[9/8]], a very common interval. The associated comma is [5671 -3578⟩.
Since the 5/4 of 1789edo is on the 576th step, a highly divisible number, 1789edo can replicate a lot of [[Ed5/4]] temperaments - more exactly those which are divisors of 576, and that includes all from [[2ed5/4]] to [[9ed5/4]], skipping [[7ed5/4]].


== Regular temperament properties ==
== Regular temperament properties ==
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|15.7
|15.7
|-
|-
|2.3
|2.3II
|{{monzo| -2836 1789 }}
|{{monzo| -2836 1789 }}
|[{{val|1789 2836}}]
|[{{val|1789 2836}}]
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|1.9
|1.9
|}
|}
== Tempered commas ==
{| class="wikitable"
|+Tempered commas in 1789edo
!Prime
Subgroup
!Val
!Ratio
!Monzo
<small>(zeroes skipped for clarity in subgroups)</small>
!Cents
!1789edo Steps
!Name
|-
|2.3
|Patent
|
|[5671 -3578⟩
|5.006
|7.464
|
|-
|2.5
|Patent
|(1251 digits/1251 digits)
|[4154,-1789⟩
|84.766
|126.371
|French decimalisma
|-
|7-limit
|Patent
|[[2401/2400]]
|[-5,-1,-2,4⟩
|0.721
|1.075
|Breedsma
|-
|2.5.11.13
|Patent
|[[6656/6655]]
|[9,-1,-3,1⟩
|0.260
|0.388
|Jacobin comma
|-
|13-limit
|1789bdeef
|[[10648/10647]]
|[3,-2,0,-1,3,-2⟩
|0.163
|0.242
|Harmonisma
|-
|2.5.11.13.31
|Patent
|387283/387200
|[-7,-2,-2,1,3⟩
|
|0.553
|
|-
|2.5.11.13.31
|Patent
|2640704/2640625
|[6,-6,3,-2,1⟩
|
|
|
|-
|2.11.13.29.31
|Patent
|3455881/3455756
|[-2,2,4,-1,-3⟩
|
|
|
|-
|2.5.11.13.29.31
|Patent
|38132480000/38130225991
|[11,4,-1,-2,-5,3⟩
|
|
|
|}
== Table of selected intervals ==
== Table of selected intervals ==
{| class="wikitable collapsible mw-collapsed"
{| class="wikitable collapsible mw-collapsed"