Hemififths: Difference between revisions

Cleanup on hatnote & infobox
Tunings: note the vals
 
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[[File: Hemififths 17et Detempering.png|thumb|Hemififths as a 58-tone 17et detempering]]
[[File: Hemififths 17et Detempering.png|thumb|Hemififths as a 58-tone 17et detempering]]


Hemififths is very naturally considered as a [[detemperament]] of the [[17edo|17 equal temperament]]. The diagram on the right shows a 58-tone detempered scale, with a generator range of -28 to +29. 58 is the largest number of tones for a mos where intervals in the 17 categories do not overlap. Each category may be further divided into "sub", "plain" and "super" qualities, separated by -17 generator steps, which represents the syntonic~septimal comma. Combining this division with the minor, neutral, and major qualities of the 17 equal temperament, hemififths gives us at least ''nine'' qualities for each diatonic category: subminor, minor, supraminor, subneutral, neutral, supraneutral, submajor, major, and supermajor.  
Hemififths is very naturally considered as a [[detemperament]] of the [[17edo|17 equal temperament]]. The diagram on the right shows a 58-tone detempered scale, with a generator range of -28 to +29. 58 is the largest number of tones for a mos where intervals in the 17 categories do not overlap. Each category may be further divided into "sub", "plain" and "super" qualities, separated by the commatic step of -17 generator steps, which represents [[56/55]], [[64/63]], [[66/65]], [[78/77]], [[81/80]], [[91/90]], [[99/98]], [[121/120]], and [[169/168]]. Combining this division with the minor, neutral, and major qualities of the 17 equal temperament, hemififths gives us at least ''nine'' qualities for each diatonic category: subminor, minor, supraminor, subneutral, neutral, supraneutral, submajor, major, and supermajor.  


Notice also the little interval between the largest of a category and the smallest of the next. This interval separates supraminor from subneutral and supraneutral from submajor, and spans 41 generator steps. 41edo tempers it out so that it conflates supraminor with subneutral and supraneutral with submajor, whereas 58edo exaggerates it to the size of the syntonic~septimal comma. 99edo tunes it to one half the size of the syntonic~septimal comma, which can be seen as a good compromise.
Notice also the little interval between the largest of a category and the smallest of the next. This interval separates supraminor from subneutral and supraneutral from submajor, and spans 41 generator steps. 41edo tempers it out so that it conflates supraminor with subneutral and supraneutral with submajor, whereas 58edo exaggerates it to the size of the comma. 99edo tunes it to one half the size of the commatic step, which can be seen as a good compromise.


== Notation ==
== Notation ==
Hemififths can be notated in [[neutral chain-of-fifths notation]], in which case 5/4 is represented by a sesqui-augmented second (C–D{{sesquisharp2}}), and 7/4 by a semi-augmented sixth (C–A{{demisharp2}}). In the 13-limit extension, 11/8 is represented by the semi-augmented fourth (C–F{{demisharp2}}), and 13/8 by the neutral sixth (C–A{{demiflat2}}). This, of course, defies the tradition of tertian harmony. The just major triad on C is {{dash|C, D{{sesquisharp2}}, G|med}}, for example. One may want to adopt one or more additional modules of accidentals such as arrows or +/- signs to represent the comma steps. There are two notable comma steps:
Hemififths can be notated in [[neutral chain-of-fifths notation]], in which case 5/4 is represented by a sesqui-augmented second (C–D{{sesquisharp2}}), and 7/4 by a semi-augmented sixth (C–A{{demisharp2}}). In the 13-limit extension, 11/8 is represented by the semi-augmented fourth (C–F{{demisharp2}}), and 13/8 by the neutral sixth (C–A{{demiflat2}}). This, of course, defies the tradition of tertian harmony, as the [[just major triad]] on C is C–D{{sesquisharp2}}–G, for example, so one may want to adopt one or more additional modules of accidentals such as arrows or +/- signs to represent the commatic steps (-17 generator steps, a semidiminished second).
# The syntonic~septimal comma (-17 gensteps, semidiminished second);
 
# The Pythagorean comma (+24 gensteps, inverse diminished second).  
Below is tabulated how to notate each prime harmonic with an arrow representing a commatic step (thus ↑C = D{{sesquiflat2}}).  


Below is tabulated how to notate the prime harmonics with an arrow representing a syntonic~septimal comma (thus ^C = Ddb).
{| class="wikitable center-1 center-3"
{| class="wikitable center-1 center-3"
|+ style="font-size: 105%;" | Hemififths nomenclature<br>for selected intervals
|+ style="font-size: 105%;" | Hemififths nomenclature<br>for selected intervals
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| 5/4
| 5/4
| Down major third
| Down major third
| C–vE
| C–↓E
|-
|-
| 7/4
| 7/4
| Down minor seventh
| Down minor seventh
| C–vBb
| C–↓B♭
|-
| 11/8
| Semi-augmented fourth
| C–Ft
|-
| 13/8
| Neutral sixth
| C–Ad
|}
 
Below is tabulated how to notate the prime harmonics with an arrow representing a Pythagorean comma (thus ^C = B#).
{| class="wikitable center-1 center-3"
|+ style="font-size: 105%;" | Hemififths nomenclature<br>for selected intervals
|-
! Ratio
! Nominal
! Example
|-
| 3/2
| Perfect fifth
| C–G
|-
| 5/4
| Up neutral third
| C–^Ed
|-
| 7/4
| Up semidiminished seventh
| C–^Bdb
|-
|-
| 11/8
| 11/8
| Semi-augmented fourth
| Semi-augmented fourth
| C–Ft
| C–F{{demisharp2}}
|-
|-
| 13/8
| 13/8
| Neutral sixth
| Neutral sixth
| C–Ad
| C–A{{demiflat2}}
|}
|}


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|  
|  
| 350.000
| 350.000
| Lower bound of 7- and 9-odd-limit diamond monotone
| 24c val, lower bound of 7- and 9-odd-limit diamond monotone
|-
|-
|  
|  
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|  
|  
| 351.220
| 351.220
| Lower bound of 11- to 15-odd-limit<br>and (13-limit) 21-odd-limit diamond monotone
| Lower bound of 11- to 15-odd-limit, <br>and 13-limit 21-odd-limit diamond monotone
|-
|-
|  
|  
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|  
|  
| 351.429
| 351.429
|  
| 140ef val
|-
|-
|  
|  
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| 25/24
| 25/24
| 351.472
| 351.472
| Very close to [[Argent tuning|argent tuning]] with neutral intervals (351.47186 cents)
| Very close to [[argent tuning]] with neutral intervals (351.47186 cents)
|-
|-
|  
|  
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|  
|  
| 351.515
| 351.515
|  
| 99ef val
|-
|-
|  
|  
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| 15/13
| 15/13
| 351.705
| 351.705
| 15-odd-limit and (13-limit) 21-odd-limit minimax
| 15-odd-limit and 13-limit 21-odd-limit minimax
|-
|-
| [[58edo|17\58]]
| [[58edo|17\58]]
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|  
|  
| 352.000
| 352.000
|  
| 75ce val
|-
|-
|  
|  
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|  
|  
| 352.941
| 352.941
| Upper bound of 7- to 15-odd-limit<br>and (13-limit) 21-odd-limit diamond monotone
| 17c val, upper bound of 7- to 15-odd-limit, <br>and 13-limit 21-odd-limit diamond monotone
|-
|-
|  
|  
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[[Category:Rank-2 temperaments]]
[[Category:Rank-2 temperaments]]
[[Category:Breedsmic temperaments]]
[[Category:Breedsmic temperaments]]
[[Category:Hemifamity temperaments]]
[[Category:Aberschismic temperaments]]
[[Category:Hemimage temperaments]]
[[Category:Hemimage temperaments]]