Porcupine family

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This is a list showing technical temperament data. For an explanation of what information is shown here, you may look at the technical data guide for regular temperaments.

The porcupine family of temperaments tempers out the porcupine comma, 250/243, also called the maximal diesis.

Porcupine

The generator of porcupine is a minor whole tone, the 10/9 interval, and three of these add up to a perfect fourth (4/3), with two more giving the minor sixth (8/5). In fact, (10/9)3 = (4/3)⋅(250/243), and (10/9)5 = (8/5)⋅(250/243)2. Its ploidacot is omega-tricot. 3\22 is a very recommendable generator, and mos scales of 7, 8 and 15 notes make for some nice scale possibilities.

Subgroup: 2.3.5

Comma list: 250/243

Mapping[1 2 3], 0 -3 -5]]

mapping generators: ~2, ~10/9

Optimal tunings:

  • CTE: ~2 = 1200.000, ~10/9 = 164.166
error map: 0.000 +5.547 -7.143]
  • POTE: ~2 = 1200.000, ~10/9 = 163.950
error map: 0.000 +6.194 -6.065]

Tuning ranges:

Optimal ET sequence7, 15, 22, 95c

Badness (Smith): 0.030778

Overview to extensions

7-limit extensions

The second comma defines which 7-limit family member we are looking at.

  • Hystrix adds 36/35, the mint comma, for a tuning sharp of 8d-edo;
  • Opossum adds 28/27, the trienstonic comma, for a tuning between 8d-edo and 15edo;
  • Septimal porcupine adds 64/63, the archytas comma, for a tuning between 15edo and 22edo;
  • Porky adds 225/224, the marvel comma, for a tuning between 22edo and 29edo;
  • Coendou adds 525/512, the avicennma, for a tuning flat of 29edo.

Those all share the same generator with porcupine.

nautilus tempers out 49/48 and splits the generator in two. hedgehog tempers out 50/49 with a semi-octave period. Finally, ammonite tempers out 686/675 and ceratitid tempers out 1728/1715. Those split the generator in three.

Temperaments discussed elsewhere include:

Subgroup extensions

Noting that 250/243 = (55/54)⋅(100/99) = S102S11, the temperament thus extends naturally to the 2.3.5.11 subgroup, sometimes known as porkypine, given right below.

2.3.5.11 subgroup (porkypine)

Subgroup: 2.3.5.11

Comma list: 55/54, 100/99

Sval mapping: [1 2 3 4], 0 -3 -5 -4]]

Gencom mapping: [1 2 3 0 4], 0 -3 -5 0 -4]]

gencom: [2 10/9; 55/54, 100/99]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 163.887
  • POTE: ~2 = 1200.000, ~11/10 = 164.078

Optimal ET sequence: 7, 15, 22, 73ce, 95ce

Badness (Smith): 0.0097

Undecimation

Subgroup: 2.3.5.11.13

Comma list: 55/54, 100/99, 512/507

Sval mapping: [1 5 8 8 2], 0 -6 -10 -8 3]]

sval mapping generators: ~2, ~65/44

Optimal tunings:

  • CTE: ~2 = 1200.000, ~88/65 = 518.086
  • POTE: ~2 = 1200.000, ~88/65 = 518.209

Optimal ET sequence: 7, 23bc, 30, 37, 44

Badness (Smith): 0.0305

Septimal porcupine

Septimal porcupine uses six of its minor tone generator steps to get to 7/4. Here, we share the same mapping of 7/4 in terms of fifths as archy. For this to work you need a small minor tone such as 22edo provides, and once again 3\22 is a good tuning choice, though we might pick in preference 8\59, 11\81, or 19\140 for our generator.

Subgroup: 2.3.5.7

Comma list: 64/63, 250/243

Mapping[1 2 3 2], 0 -3 -5 6]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~10/9 = 163.203
error map: 0.000 +8.435 -2.330 +10.394]
  • POTE: ~2 = 1200.000, ~10/9 = 162.880
error map: 0.000 +9.405 -0.714 +8.455]

Minimax tuning:

unchanged-interval (eigenmonzo) basis: 2.5
unchanged-interval (eigenmonzo) basis: 2.9/7

Tuning ranges:

  • 7- and 9-odd-limit diamond monotone: ~10/9 = [160.000, 163.636] (2\15 to 3\22)
  • 7-odd-limit diamond tradeoff: ~10/9 = [157.821, 166.015]
  • 9-odd-limit diamond tradeoff: ~10/9 = [157.821, 182.404]

Optimal ET sequence7, 15, 22, 37, 59, 81bd

Badness (Smith): 0.041057

11-limit

Subgroup: 2.3.5.7.11

Comma list: 55/54, 64/63, 100/99

Mapping: [1 2 3 2 4], 0 -3 -5 6 -4]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 163.105
  • POTE: ~2 = 1200.000, ~11/10 = 162.747

Minimax tuning:

  • 11-odd-limit: ~11/10 = [1/6 -1/6 0 1/12
unchanged-interval (eigenmonzo) basis: 2.9/7

Tuning ranges:

  • 11-odd-limit diamond monotone: ~11/10 = [160.000, 163.636] (2\15 to 3\22)
  • 11-odd-limit diamond tradeoff: ~11/10 = [150.637, 182.404]

Optimal ET sequence: 7, 15, 22, 37, 59

Badness (Smith): 0.021562

Porcupinefowl

This extension used to be tridecimal porcupine.

Subgroup: 2.3.5.7.11.13

Comma list: 40/39, 55/54, 64/63, 66/65

Mapping: [1 2 3 2 4 4], 0 -3 -5 6 -4 -2]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 163.442
  • POTE: ~2 = 1200.000, ~11/10 = 162.708

Minimax tuning:

  • 13- and 15-odd-limit: ~10/9 = [1 0 0 0 -1/4
unchanged-interval (eigenmonzo) basis: 2.11

Tuning ranges:

  • 13-odd-limit diamond monotone: ~11/10 = [160.000, 163.636] (2\15 to 3\22)
  • 15-odd-limit diamond monotone: ~11/10 = 163.636 (3\22)
  • 13- and 15-odd-limit diamond tradeoff: ~11/10 = [138.573, 182.404]

Optimal ET sequence: 7, 15, 22f, 37f

Badness (Smith): 0.021276

Porcupinefish

Subgroup: 2.3.5.7.11.13

Comma list: 55/54, 64/63, 91/90, 100/99

Mapping: [1 2 3 2 4 6], 0 -3 -5 6 -4 -17]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 162.636
  • POTE: ~2 = 1200.000, ~11/10 = 162.277

Minimax tuning:

  • 13- and 15-odd-limit: ~10/9 = [2/13 0 0 0 1/13 -1/13
unchanged-interval (eigenmonzo) basis: 2.13/11

Tuning ranges:

  • 13-odd-limit diamond monotone: ~10/9 = [160.000, 162.162] (2\15 to 5\37)
  • 15-odd-limit diamond monotone: ~10/9 = 162.162 (5\37)
  • 13- and 15-odd-limit diamond tradeoff: ~10/9 = [150.637, 182.404]

Optimal ET sequence: 15, 22, 37

Badness (Smith): 0.025314

Pourcup

Subgroup: 2.3.5.7.11.13

Comma list: 55/54, 64/63, 100/99, 196/195

Mapping: [1 2 3 2 4 1], 0 -3 -5 6 -4 20]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 163.378
  • POTE: ~2 = 1200.000, ~11/10 = 162.482

Minimax tuning:

  • 13- and 15-odd-limit: ~11/10 = [1/14 0 0 -1/14 0 1/14
unchanged-interval (eigenmonzo) basis: 2.13/7

Optimal ET sequence: 15f, 22f, 37, 59f

Badness (Smith): 0.035130

Porkpie

Subgroup: 2.3.5.7.11.13

Comma list: 55/54, 64/63, 65/63, 100/99

Mapping: [1 2 3 2 4 3], 0 -3 -5 6 -4 5]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 163.678
  • POTE: ~2 = 1200.000, ~11/10 = 163.688

Minimax tuning:

  • 13- and 15-odd-limit: ~11/10 = [1/6 -1/6 0 1/12
unchanged-interval (eigenmonzo) basis: 2.9/7

Optimal ET sequence: 7, 15f, 22

Badness (Smith): 0.026043

Opossum

Opossum can be described as 8d & 15. Tempering out 28/27, the perfect fifth of three generator steps is conflated with not 32/21 as in porcupine but 14/9. Three such fifths or nine generator steps octave reduced give a flat 7/4. 2\15 is a good generator.

Subgroup: 2.3.5.7

Comma list: 28/27, 126/125

Mapping[1 2 3 4], 0 -3 -5 -9]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~10/9 = 161.306
error map: 0.000 +14.126 +7.155 -20.583]
  • POTE: ~2 = 1200.000, ~10/9 = 159.691
error map: 0.000 +18.971 +15.229 -6.048]

Minimax tuning:

Optimal ET sequence7d, 8d, 15

Badness (Smith): 0.040650

11-limit

Subgroup: 2.3.5.7.11

Comma list: 28/27, 55/54, 77/75

Mapping: [1 2 3 4 4], 0 -3 -5 -9 -4]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 161.365
  • POTE: ~2 = 1200.000, ~11/10 = 159.807

Minimax tuning:

  • 11-odd-limit unchanged-interval (eigenmonzo) basis: 2.7

Optimal ET sequence: 7d, 8d, 15

Badness (Smith): 0.022325

13-limit

Subgroup: 2.3.5.7.11.13

Comma list: 28/27, 40/39, 55/54, 66/65

Mapping: [1 2 3 4 4 4], 0 -3 -5 -9 -4 -2]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 161.631
  • POTE: ~2 = 1200.000, ~11/10 = 158.805

Minimax tuning:

  • 13- and 15-odd-limit unchanged-interval (eigenmonzo) basis: 2.7

Optimal ET sequence: 7d, 8d, 15, 38bceff

Badness (Smith): 0.019389

Porky

Porky can be described as 22 & 29, suggesting a less sharp perfect fifth. 7\51 is a good generator.

Subgroup: 2.3.5.7

Comma list: 225/224, 250/243

Mapping[1 2 3 5], 0 -3 -5 -16]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~10/9 = 164.391
error map: 0.000 +4.871 -8.270 +0.913]
  • POTE: ~2 = 1200.000, ~10/9 = 164.412
error map: 0.000 +4.809 -8.375 +0.580]

Minimax tuning:

unchanged-interval (eigenmonzo) basis: 2.7/5

Optimal ET sequence7d, 15d, 22, 29, 51, 73c

Badness (Smith): 0.054389

11-limit

Subgroup: 2.3.5.7.11

Comma list: 55/54, 100/99, 225/224

Mapping: [1 2 3 5 4], 0 -3 -5 -16 -4]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 164.321
  • POTE: ~2 = 1200.000, ~11/10 = 164.552

Minimax tuning:

  • 11-odd-limit: ~11/10 = [2/11 0 1/11 -1/11
unchanged-interval (eigenmonzo) basis: 2.7/5

Optimal ET sequence: 7d, 15d, 22, 51

Badness (Smith): 0.027268

13-limit

Subgroup: 2.3.5.7.11.13

Comma list: 55/54, 65/64, 91/90, 100/99

Mapping: [1 2 3 5 4 3], 0 -3 -5 -16 -4 5]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 164.478
  • POTE: ~2 = 1200.000, ~11/10 = 164.953

Optimal ET sequence: 7d, 22, 29, 51f, 80cdeff

Badness (Smith): 0.026543

Music

Coendou

Coendou can be described as 29 & 36c, suggesting an even less sharp or near-just perfect fifth. 9\65 is a good generator.

Subgroup: 2.3.5.7

Comma list: 250/243, 525/512

Mapping[1 2 3 1], 0 -3 -5 13]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~10/9 = 166.094
error map: 0.000 -0.236 -16.783 -9.607]
  • POTE: ~2 = 1200.000, ~10/9 = 166.041
error map: 0.000 -0.077 -16.516 -10.299]

Minimax tuning:

unchanged-interval (eigenmonzo) basis: 2.3

Optimal ET sequence7, 22d, 29, 65c, 94cd

Badness (Smith): 0.118344

11-limit

Subgroup: 2.3.5.7.11

Comma list: 55/54, 100/99, 525/512

Mapping: [1 2 3 1 4], 0 -3 -5 13 -4]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 165.925
  • POTE: ~2 = 1200.000, ~11/10 = 165.981

Minimax tuning:

  • 11-odd-limit: ~11/10 = [2/3 -1/3
unchanged-interval (eigenmonzo) basis: 2.3

Optimal ET sequence: 7, 22d, 29, 65ce

Badness (Smith): 0.049669

13-limit

Subgroup: 2.3.5.7.11.13

Comma list: 55/54, 65/64, 100/99, 105/104

Mapping: [1 2 3 1 4 3], 0 -3 -5 13 -4 5]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 166.046
  • POTE: ~2 = 1200.000, ~11/10 = 165.974

Minimax tuning:

  • 13- and 15-odd-limit: ~11/10 = [2/3 -1/3
unchanged-interval (eigenmonzo) basis: 2.3

Optimal ET sequence: 7, 22d, 29, 65cef

Badness (Smith): 0.030233

Hystrix

Hystrix provides a less complex avenue to the 7-limit, with the generator taking on the role of approximating 8/7. Unfortunately in temperaments as in life you get what you pay for, and hystrix is very high in error due to the large disparity between typical porcupine generators and a justly-tuned 8/7, and is usually considered an exotemperament. A generator of 2\15 or 9\68 can be used for hystrix.

Subgroup: 2.3.5.7

Comma list: 36/35, 160/147

Mapping[1 2 3 3], 0 -3 -5 -1]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~10/9 = 165.185
error map: 0.000 +2.491 -12.236 +65.990]
  • POTE: ~2 = 1200.000, ~10/9 = 158.868
error map: 0.000 +21.442 +19.348 +72.306]

Minimax tuning:

unchanged-interval (eigenmonzo) basis: 2.5

Optimal ET sequence7, 8d, 15d

Badness (Smith): 0.044944

11-limit

Subgroup: 2.3.5.7.11

Comma list: 22/21, 36/35, 80/77

Mapping: [1 2 3 3 4], 0 -3 -5 -1 -4]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~11/10 = 164.768
  • POTE: ~2 = 1200.000, ~11/10 = 158.750

Optimal ET sequence: 7, 8d, 15d

Badness (Smith): 0.026790

Hedgehog

Hedgehog has a period 1/2 octave and a generator which can be taken to be 9/7 instead of 10/9. It also tempers out 245/243, the sensamagic comma. It is a strong extension of BPS (as BPS has no 2 or sqrt(2)). Its ploidacot is diploid omega-tricot.

22edo provides an obvious tuning, which happens to be the only patent-val tuning, but if you are looking for an alternative you could try the 146 232 338 411] (146bccdd) val with generator 10\73, or you could try 164 cents if you are fond of round numbers. The 14-note mos gives scope for harmony while stopping well short of 22. A related temperament is echidna, which offers much more accuracy. They merge on 22edo.

Subgroup: 2.3.5.7

Comma list: 50/49, 245/243

Mapping[2 1 1 2], 0 3 5 5]]

mapping generators: ~7/5, ~9/7

Optimal tunings:

  • CTE: ~7/5 = 600.000, ~9/7 = 435.258
error map: 0.000 +3.819 -10.024 +7.464]
  • POTE: ~7/5 = 600.000, ~9/7 = 435.648
error map: 0.000 +4.989 -8.074 +9.414]

Optimal ET sequence8d, 14c, 22

Badness (Smith): 0.043983

11-limit

Subgroup: 2.3.5.7.11

Comma list: 50/49, 55/54, 99/98

Mapping: [2 1 1 2 4], 0 3 5 5 4]]

Optimal tunings:

  • CTE: ~7/5 = 600.000, ~9/7 = 435.528
  • POTE: ~7/5 = 600.000, ~9/7 = 435.386

Optimal ET sequence: 8d, 14c, 22, 58ce

Badness (Smith): 0.023095

13-limit

Subgroup: 2.3.5.7.11.13

Comma list: 50/49, 55/54, 65/63, 99/98

Mapping: [2 1 1 2 4 3], 0 3 5 5 4 6]]

Optimal tunings:

  • CTE: ~7/5 = 600.000, ~9/7 = 436.309
  • POTE: ~7/5 = 600.000, ~9/7 = 435.861

Optimal ET sequence: 8d, 14cf, 22

Badness (Smith): 0.021516

Urchin

Subgroup: 2.3.5.7.11.13

Comma list: 40/39, 50/49, 55/54, 66/65

Mapping: [2 1 1 2 4 6], 0 3 5 5 4 2]]

Optimal tunings:

  • CTE: ~7/5 = 600.000, ~9/7 = 435.186
  • POTE: ~7/5 = 600.000, ~9/7 = 437.078

Optimal ET sequence: 14c, 22f

Badness (Smith): 0.025233

Hedgepig

Subgroup: 2.3.5.7.11

Comma list: 50/49, 245/243, 385/384

Mapping: [2 1 1 2 12], 0 3 5 5 -7]]

Optimal tunings:

  • CTE: ~7/5 = 600.000, ~9/7 = 435.329
  • POTE: ~7/5 = 600.000, ~9/7 = 435.425

Optimal ET sequence: 22

Badness (Smith): 0.068406

Music

Nautilus

Nautilus tempers out 49/48 and may be described as the 14c & 15 temperament. Its ploidacot is omega-hexacot.

Subgroup: 2.3.5.7

Comma list: 49/48, 250/243

Mapping[1 2 3 3], 0 -6 -10 -3]]

mapping generators: ~2, ~21/20

Optimal tunings:

  • CTE: ~2 = 1200.000, ~21/20 = 81.914
error map: 0.000 +6.559 -5.457 -14.569]
  • POTE: ~2 = 1200.000, ~21/20 = 82.505
error map: 0.000 +3.012 -11.368 -16.342]

Optimal ET sequence14c, 15, 29, 44d

Badness (Smith): 0.057420

11-limit

Subgroup: 2.3.5.7.11

Comma list: 49/48, 55/54, 245/242

Mapping: [1 2 3 3 4], 0 -6 -10 -3 -8]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~21/20 = 81.802
  • POTE: ~2 = 1200.000, ~21/20 = 82.504

Optimal ET sequence: 14c, 15, 29, 44d

Badness (Smith): 0.026023

13-limit

Subgroup: 2.3.5.7.11.13

Comma list: 49/48, 55/54, 91/90, 100/99

Mapping: [1 2 3 3 4 5], 0 -6 -10 -3 -8 -19]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~21/20 = 81.912
  • POTE: ~2 = 1200.000, ~21/20 = 82.530

Optimal ET sequence: 14cf, 15, 29, 44d

Badness (Smith): 0.022285

Belauensis

Subgroup: 2.3.5.7.11.13

Comma list: 40/39, 49/48, 55/54, 66/65

Mapping: [1 2 3 3 4 4], 0 -6 -10 -3 -8 -4]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~21/20 = 82.034
  • POTE: ~2 = 1200.000, ~21/20 = 81.759

Optimal ET sequence: 14c, 15, 29f, 44dff

Badness (Smith): 0.029816

Music

Ammonite

Ammonite adds 686/675 to the comma list and may be described as the 8d & 29 temperament. Its ploidacot is epsilon-enneacot. 37edo provides an obvious tuning.

Subgroup: 2.3.5.7

Comma list: 250/243, 686/675

Mapping[1 5 8 10], 0 -9 -15 -19]]

mapping generators: ~2, ~9/7

Optimal tunings:

  • CTE: ~2 = 1200.000, ~9/7 = 454.550
error map: 0.000 +7.095 -4.564 -5.276]
  • POTE: ~2 = 1200.000, ~9/7 = 454.448
error map: 0.000 +8.009 -3.040 -3.346]

Optimal ET sequence8d, 21cd, 29, 37, 66

Badness (Smith): 0.107686

11-limit

Subgroup: 2.3.5.7.11

Comma list: 55/54, 100/99, 686/675

Mapping: [1 5 8 10 8], 0 -9 -15 -19 -12]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~9/7 = 454.505
  • POTE: ~2 = 1200.000, ~9/7 = 454.512

Optimal ET sequence: 8d, 21cde, 29, 37, 66

Badness (Smith): 0.045694

13-limit

Subgroup: 2.3.5.7.11.13

Comma list: 55/54, 91/90, 100/99, 169/168

Mapping: [1 5 8 10 8 9], 0 -9 -15 -19 -12 -14]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~13/10 = 454.480
  • POTE: ~2 = 1200.000, ~13/10 = 454.529

Optimal ET sequence: 8d, 21cdef, 29, 37, 66

Badness (Smith): 0.027168

Ceratitid

Ceratitid adds 1728/1715 to the comma list and may be described as the 21c & 22 temperament. Its ploidacot is omega-enneacot. 22edo provides an obvious tuning.

Subgroup: 2.3.5.7

Comma list: 250/243, 1728/1715

Mapping[1 2 3 3], 0 -9 -15 -4]]

mapping generators: ~2, ~36/35

Optimal tunings:

  • CTE: ~2 = 1200.000, ~36/35 = 54.804
error map: 0.000 +4.809 -8.374 +11.958]
  • POTE: ~2 = 1200.000, ~36/35 = 54.384
error map: 0.000 +8.585 -2.081 +13.636]

Optimal ET sequence1c, 21c, 22

Badness (Smith): 0.115304

11-limit

Subgroup: 2.3.5.7.11

Comma list: 55/54, 100/99, 352/343

Mapping: [1 2 3 3 4], 0 -9 -15 -4 -12]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~36/35 = 54.702
  • POTE: ~2 = 1200.000, ~36/35 = 54.376

Optimal ET sequence: 1ce, 21ce, 22

Badness (Smith): 0.051319

13-limit

Subgroup: 2.3.5.7.11.13

Comma list: 55/54, 65/63, 100/99, 352/343

Mapping: [1 2 3 3 4 4], 0 -9 -15 -4 -12 -7]]

Optimal tunings:

  • CTE: ~2 = 1200.000, ~36/35 = 54.575
  • POTE: ~2 = 1200.000, ~36/35 = 54.665

Optimal ET sequence: 1ce, 21cef, 22

Badness (Smith): 0.044739