Porcupine family
- 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
- 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]
- 5-odd-limit diamond monotone: ~10/9 = [150.000, 171.429] (1\8 to 1\7)
- 5-odd-limit diamond tradeoff: ~10/9 = [157.821, 166.015]
Optimal ET sequence: 7, 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) = S102⋅S11, 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]]
- 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]
- 7-odd-limit: ~10/9 = [3/5 0 -1/5⟩
- 9-odd-limit: ~10/9 = [1/6 -1/6 0 1/12⟩
- 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 sequence: 7, 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]]
- 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]
Optimal ET sequence: 7d, 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]]
- 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]
- 7- and 9-odd-limit: ~10/9 = [2/11 0 1/11 -1/11⟩
Optimal ET sequence: 7d, 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
- Improvisation in 29edo (2024) by Budjarn Lambeth – in Palace scale, 29edo tuning
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]]
- 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]
- 7- and 9-odd-limit: ~10/9 = [2/3 -1/3⟩
Optimal ET sequence: 7, 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]]
- 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]
- 7- and 9-odd-limit: ~10/9 = [3/5 0 -1/5⟩
Optimal ET sequence: 7, 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
- 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 sequence: 8d, 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
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
- Phobos Light by Chris Vaisvil – in hedgehog[14], 22edo tuning.
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
- 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 sequence: 14c, 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
- 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 sequence: 8d, 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
- 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 sequence: 1c, 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