User:Romeolz/Isomorphic layouts/Harmonic Table extensions: Difference between revisions

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fourths, blackwood continuum and table math
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I will refer to "pure HT" when talking exclusively about layouts that map 5/4, 6/5 and 3/2 to the same location as the 12edo HT (including reflections and rotations).
I will refer to "pure HT" when talking exclusively about layouts that map 5/4, 6/5 and 3/2 to the same location as the 12edo HT (including reflections and rotations).
=== Legend ===
* dim oct = octave derived from diminished temperament, 2/1 ~ (6/5)^4, NOT A LITERAL DIMINISHED OCTAVE (ex. C4-Cb5)
* aug oct = octave derived from augmented temperament, 2/1 ~ (5/4)^3, NOT A LITERAL AUGMENTED OCTAVE (ex. C4-C#5)
* when one of these is crossed out, it means that octave mapping is no longer there and maps to another interval, and the arrow signifies where it would have been
* magic twelfth = twelfth derived from magic temperament (and so on...)
[[File:12edo harmonic table augmented diminished octave and unison.png|none|thumb|900x900px|12edo HT for reference]]
[[File:12edo harmonic table augmented diminished octave and unison.png|none|thumb|900x900px|12edo HT for reference]]


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"Why such few temperaments? Where is meantone? Why do some temperaments not work?"
"Why such few temperaments? Where is meantone? Why do some temperaments not work?"


A prerequisite for a HT-ish layout is that a single octave is reachable using some combination of the two chosen harmonically close intervals. Using meantone's fifths and thirds we can only reach the double-octave. (this probably has something to do with the monzos of the intervals and commas but I don't know how yet)
A prerequisite for a HT-ish layout is that a single octave is reachable using some combination of the two chosen harmonically close intervals (usually 3/2 and 5/4). Using meantone's fifths and thirds we can only reach the double-octave. (this probably has something to do with the monzos of the intervals and commas but I don't know how yet)
 
It is always possible to reach the octave in any ET where the interval sizes are coprime, so the ET doesn't have to support any of these temperaments. Using a HT-like layout like this is highly impractical.


== Alternate thirds ==
== Alternate thirds ==
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==== Magi ====
==== Magi ====
[[File:"HT" fourths 440cent.png|none|thumb|600x600px|fgdfjhfgds]]
[[File:"HT" fourths 440cent.png|none|thumb|600x600px|fgdfjhfgds]]
Coming up with an equivalence continuum is tough for this one because the generator varies so much. If one were to choose a single JI interval all these should be approximating, the simple temperaments would be unrecognizable.
Coming up with an equivalence continuum is tough for this one because the generator varies so much. If one were to choose a single JI interval all these should be approximating, the simple temperaments would be unrecognizable.  
[[File:ProjectiveTuningSpace fourths augmented A.png|thumb|Image A]]
[[File:ProjectiveTuningSpace fourths augmented B.png|thumb|Image B]]
{| class="wikitable"
{| class="wikitable"
|+Continuation of fourths-axial augmented "HT" into various equivalence continua
|+Continuation of fourths-axial augmented "HT" into various equivalence continua
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!5/3
!5/3
2
2
|-
!image
!
!A
!B
!todo
|-
|-
!
!
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==== Orwell/Orson (fourths ver.) ====
==== Orwell/Orson (fourths ver.) ====
[[File:"HT" fourths orwell.png|none|thumb|600x600px|hfhdgfsh]]
[[File:"HT" fourths orwell.png|none|thumb|600x600px|hfhdgfsh]]
Same thing as with the above table.
[[File:ProjectiveTuningSpace fourths diminished A.png|thumb|Image A]]
[[File:ProjectiveTuningSpace fourths diminished B.png|thumb|Image B]]
Same thing as with the above table.  
{| class="wikitable"
{| class="wikitable"
|+
|+Continuation of fourths-axial diminished "HT" into various equivalence continua
!
!
!m
!m
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!5/4
!5/4
1
1
|-
!image
!
!A
!B
|-
|-
!
!
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=== Alternate sixths/seconds ===
=== Alternate sixths/seconds ===
asdfhjköä
todo


== Hemifourths/fifths (???) ==
== Hemifourths/fifths (might be outside the scope) ==