User:Eliora/Concoctic scale: Difference between revisions

Eliora (talk | contribs)
Concoctic scales in EDOs: clarified and added other temps that make more sense
Eliora (talk | contribs)
Mathematical definition: added more precise explanation of ortho- and para-
Line 3: Line 3:
12edo 5L2s diatonic scale, the predominantly used scale in the world's music today, is an example.
12edo 5L2s diatonic scale, the predominantly used scale in the world's music today, is an example.


== Mathematical definition ==
== Mathematical derivation ==
The length of a maximum evenness scale's generator can be determined through a '''modular multiplicative inverse''' of the note amount and the tuning size<ref>https://individual.utoronto.ca/kalendis/leap/index.htm</ref>:
The length of a maximum evenness scale's generator can be determined through a '''modular multiplicative inverse''' of the note amount and the tuning size<ref>https://individual.utoronto.ca/kalendis/leap/index.htm</ref>.


<math>ax \equiv 1\mod N</math>,
<math>ax \equiv 1\mod N</math>,
Line 16: Line 16:
<math>a^2 \equiv 1\mod N \hspace{4cm} (1)</math>.
<math>a^2 \equiv 1\mod N \hspace{4cm} (1)</math>.


There are also paraconcoctic scales, or chroma-negative concoctic scales. The formula for such a scale is  
A scale is called '''orthoconcoctic''', if the generator corresponding to note amount is the chroma-positive generator, for example - the 12edo diatonic scale is. There are also '''paraconcoctic''' scales, or chroma-negative concoctic scales. The formula for such a scale is  


<math>a^2 \equiv -1\mod N \hspace{4cm} (2)</math>.
<math>a^2 \equiv -1\mod N \hspace{4cm} (2)</math>.


Since octave-inverting the MOS generator has no impact on the scale, paraconcoctic scales are identical to their usual, orthoconcoctic counterparts. However, the difference is pronounced in keyboard making - in terms of chroma direction, the white keys' generator will be the amount of black keys and vice versa.  
Since octave-inverting the MOS generator has no impact on the scale, paraconcoctic scales are identical to their usual, orthoconcoctic counterparts. However, the difference is pronounced in terms of modal brightness.  


=== Example ===
=== Example ===
Line 131: Line 131:
|[[15625/15552]]*
|[[15625/15552]]*
|
|
|Forms the [[Hanson]] (11b & 15)
|*Forms the [[Hanson]] (11b & 15)
|-
|-
|16
|16