Pinetone: Difference between revisions

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The diatonic scale has a [[Step pattern|step signature]] of [[5L 2s]], meaning it has 5 large steps and 2 small step arranged in the [[step pattern]] LsLLLsL (represented in mode 0, Dorian mode). In [[Meantone]][7], the large step represents both [[9/8]] and [[10/9]], the major and minor tones (''tempering out'' the [[81/80]] interval that separates them) hence the name "Meantone". The small step represents [[16/15]] and [[27/25]] (which differ again by [[81/80]]). We write this in the form of a [[Step pattern|step signature]] and ''step mapping'' as [[5L 2s]] = (9/8~10/9, 16/15~27/25). [[Porcupine]][7] instead has a [[Step pattern|step signature]] and step mapping [[1L 6s]] = (~9/8, 10/9~27/25), hence the difference between [[10/9]] and [[27/25]], i.e., [[250/243]], is tempered out. In mode 0 it has [[step pattern]] sssLsss. [[81/80]] is called the [[Meantone comma]], and [[250/243]] is called the [[Porcupine]] comma.
The diatonic scale has a [[Step pattern|step signature]] of [[5L 2s]], meaning it has 5 large steps and 2 small step arranged in the [[step pattern]] LsLLLsL (represented in mode 0, Dorian mode). In [[Meantone]][7], the large step represents both [[9/8]] and [[10/9]], the major and minor tones (''tempering out'' the [[81/80]] interval that separates them) hence the name "Meantone". The small step represents [[16/15]] and [[27/25]] (which differ again by [[81/80]]). We write this in the form of a [[Step pattern|step signature]] and ''step mapping'' as [[5L 2s]] = (9/8~10/9, 16/15~27/25). [[Porcupine]][7] instead has a [[Step pattern|step signature]] and step mapping [[1L 6s]] = (~9/8, 10/9~27/25), hence the difference between [[10/9]] and [[27/25]], i.e., [[250/243]], is tempered out. In mode 0 it has [[step pattern]] sssLsss. [[81/80]] is called the [[Meantone comma]], and [[250/243]] is called the [[Porcupine]] comma.


We are familiar with the Zarlino/Ptolemy just major scale: 9/8 5/4 4/3 3/2 5/3 15/8 2/1. This scale has 3 large steps of [[9/8]], 2 medium steps of [[10/9]], and 2 small steps of [[16/15]], with [[step pattern]] LMsLMLs. If we temper out the difference between L and M, we get LLsLLLs, which, as mode 2 of [[Meantone]][7] is the familiar Ionian/major mode.  
We are familiar with the Zarlino/Ptolemy [[just]] major scale: 9/8 5/4 4/3 3/2 5/3 15/8 2/1. This scale has 3 large steps of [[9/8]], 2 medium steps of [[10/9]], and 2 small steps of [[16/15]], with [[step pattern]] LMsLMLs. If we temper out the difference between L and M, we get LLsLLLs, which, as mode 2 of [[Meantone]][7] is the familiar Ionian/major mode.  


Consider instead the [[just]] scale: 10/9 6/5 4/3 3/2 5/3 9/5 2/1, a just Dorian scale. This scale has 1 large step of [[9/8]], 4 medium steps of [[10/9]], and 2 small steps of [[27/25]], with step pattern MsMLMsM (mode 0). It can be represented with [[Step pattern|step signature]] and step mapping 1L 4M 2s = (9/8, 10/9, 27/25). This is our just Porcutone diatonic.If we temper out the difference between L and M, we get LsLLLsL, [[Meantone]][7] mode 0: Dorian; if we temper out instead the difference between [[10/9]] and [[27/25]], we get sssLsss, [[Porcupine]][7] mode 0, which is referred to as ''symmetric minor''. In this way, the just Porcutone diatonic represents both [[Porcupine]][7] and [[Meantone]][7].
Consider instead the [[just]] scale: 10/9 6/5 4/3 3/2 5/3 9/5 2/1, a just Dorian scale. This scale has 1 large step of [[9/8]], 4 medium steps of [[10/9]], and 2 small steps of [[27/25]], with step pattern MsMLMsM (mode 0). It can be represented with [[Step pattern|step signature]] and step mapping 1L 4M 2s = (9/8, 10/9, 27/25). This is our [[just]] Porcutone diatonic. If we temper out the difference between L and M, we get LsLLLsL, [[Meantone]][7] mode 0: Dorian; if we temper out instead the difference between [[10/9]] and [[27/25]], we get sssLsss, [[Porcupine]][7] mode 0, which is referred to as ''symmetric minor''. In this way, the [[just]] Porcutone diatonic represents both [[Porcupine]][7] and [[Meantone]][7].


To name this mode of the Porcutone diatonic, we simply add the mode names together, prefixing the [[Porcupine]][7] functional mode names introduced in Table 1., with the [[Meantone]] diatonic mode names referenced in Table 2., so mode 0 of the Porcutone diatonic is called ''Dorian symmetric minor''. Along with the step pattern and mode number, the modes' [[UDP]] are shown in Tables 1. and 2. A mode's UDP shows the number of generators in the direction the brighten the intervals of scale, followed the number of generators in the direction that darkens it, (followed by the number of periods per octave, if it is not one. In this case the scale repeats at the octave, so P = 1, and is not shown). We continue this naming process with the other 6 modes to arrive at the modes shown in Table 3.
To name this mode of the Porcutone diatonic, we simply add the mode names together, prefixing the [[Porcupine]][7] functional mode names introduced in Table 1., with the [[Meantone]] diatonic mode names referenced in Table 2., so mode 0 of the Porcutone diatonic is called ''Dorian symmetric minor''. Along with the step pattern and mode number, the modes' [[UDP]] are shown in Tables 1. and 2. A mode's UDP shows the number of generators in the direction the brighten the intervals of scale, followed the number of generators in the direction that darkens it, (followed by the number of periods per octave, if it is not one. In this case the scale repeats at the octave, so P = 1, and is not shown). We continue this naming process with the other 6 modes to arrive at the modes shown in Table 3.