Porcupine extensions: Difference between revisions

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Interval chain: Replaced "Porcupine" with "Porcupinefowl"
 
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{{Breadcrumb}}
{{Breadcrumb|Porcupine}}
[[Porcupine]] has various [[extension]]s to the [[13-limit]]. Adding the 13th harmonic to porcupine is not very simple, because 13 tends to fall in between the simple intervals produced by porcupine's generator. The extensions are:  
[[Porcupine]] has various [[extension]]s to the [[13-limit]]. Adding the 13th harmonic to porcupine is not very simple, because 13 tends to fall in between the simple intervals produced by porcupine's generator. The extensions are:  
* '''Porcupinefowl''' ({{nowrap|15 & 22f}}) – tempering out 40/39, 55/54, 64/63, and 66/65;
* '''Porcupinefowl''' ({{nowrap| 15 & 22f }}) – tempering out 40/39, 55/54, 64/63, and 66/65;
* '''Porcupinefish''' ({{nowrap|15 & 22}}) – tempering out 55/54, 64/63, 91/90, and 100/99;
* '''Porcupinefish''' ({{nowrap| 15 & 22 }}) – tempering out 55/54, 64/63, 91/90, and 100/99;
* '''Porkpie''' ({{nowrap|15f & 22}}) – tempering out 55/54, 64/63, 65/63, 100/99;
* '''Porkpie''' ({{nowrap| 15f & 22 }}) – tempering out 55/54, 64/63, 65/63, 100/99;
* '''Pourcup''' ({{nowrap|15f & 22f}}) – tempering out 55/54, 64/63, 100/99, and 196/195.  
* '''Pourcup''' ({{nowrap| 15f & 22f }}) – tempering out 55/54, 64/63, 100/99, and 196/195.  


Additionally, there are alternative extensions to prime 7:
Additionally, there are alternative extensions to prime 7:
* '''[[Opossum]]''' ({{nowrap|8d & 15}}) – tempering out 28/27, 40/39, 55/54, and 66/65.
* '''[[Opossum]]''' ({{nowrap| 8d & 15 }}) – tempering out 28/27, 40/39, 55/54, and 66/65.
* '''Porky''' ({{nowrap|22 & 29}}) – tempering out 55/54, 65/64, 91/90, and 100/99;
* '''Porky''' ({{nowrap| 22 & 29 }}) – tempering out 55/54, 65/64, 91/90, and 100/99;
* '''Coendou''' ({{nowrap|29 & 36ce}}) – tempering out 55/54, 65/64, 100/99, and 105/104.
* '''Coendou''' ({{nowrap| 29 & 36ce }}) – tempering out 55/54, 65/64, 100/99, and 105/104.


Porcupinefowl maps [[13/8]] to −2 generator steps and conflates it with [[5/3]] and [[18/11]], tempering out [[40/39]]. This is where the generator, representing [[10/9]], [[11/10]], and [[12/11]], goes one step further to stand in for ~[[13/12]]. Porkpie maps 13/8 to +5 generator steps and conflates it with [[8/5]], tempering out [[65/64]]. The generator now represents ~[[14/13]]. Without optimization for the 13-limit, porcupinefowl sharpens the interval class of 13 by about 30{{cent}}, and porkpie flattens it by about 20{{cent}}.  
Porcupinefowl maps [[13/8]] to −2 generator steps and conflates it with [[5/3]] and [[18/11]], tempering out [[40/39]]. This is where the generator, representing [[10/9]], [[11/10]], and [[12/11]], goes one step further to stand in for ~[[13/12]]. Porkpie maps 13/8 to +5 generator steps and conflates it with [[8/5]], tempering out [[65/64]]. The generator now represents ~[[14/13]]. Without optimization for the 13-limit, porcupinefowl sharpens the interval class of 13 by about 30{{cent}}, and porkpie flattens it by about 20{{cent}}.  
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== Interval chain ==
== Interval chain ==
In the following table, odd harmonics and subharmonics 1–13 are in '''bold'''.  
In the following table, odd harmonics and subharmonics 1–15 are in '''bold'''.  


{| class="wikitable center-1 right-2"
{| class="wikitable center-1 right-2"
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! colspan="4" | 13-limit extensions
! colspan="4" | 13-limit extensions
|-
|-
! Porcupine
! Porcupinefowl
! Porcupinefish
! Porcupinefish
! Porkpie
! Porkpie
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| 6
| 6
| 976.9
| 976.9
| '''7/4''', 16/9
| '''7/4''', '''16/9'''
| 26/15
| 26/15
|  
|  
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| 8
| 8
| 102.5
| 102.5
| 16/15, 21/20
| '''16/15''', 21/20
| 14/13, 26/25
| 14/13, 26/25
| 27/26
| 27/26
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|-
|-
! Edo<br>generator
! Edo<br>generator
! Eigenmonzo<br>(unchanged-interval)
! Unchanged interval<br>(eigenmonzo)
! Generator (¢)
! Generator (¢)
! Comments
! Comments