User:Contribution/Collection of tunings
Equal-step tunings
About this list
The table that follows is not a “best-of” roster but a modest snapshot of equal-step tunings that happen to score highly under a few specific mathematical lenses. In particular, it gathers:
- Prominent peak counts from the classic Riemann zeta function
- Prominent peaks after removing the prime 2 from the zeta product
- Prominent peaks after removing the prime 3
- Prominent peaks after simultaneously removing the primes 2 and 3
- The α–β–γ family, with an equave sliding from 3/1 down to 4/3
These tunings earn the label “optimized” only relative to the limited set of zeta-derived functions explored here. When you layer many differently pruned zeta functions in a tool such as Wolfram Mathematica, striking peaks emerge almost everywhere; the peaks simply shift as each combination of omitted primes reshapes the landscape. That ubiquity means there is no absolute “good” or “bad” equal-step tuning, only different alignments of primes that reveal different musical affordances.
Consequently, the list below is inherently biased toward a handful of functions and can only hint at the boundless diversity of xenharmonic equal-step systems. Treat it as a useful starting palette, not a definitive canon.
Notable Local Maxima of the Riemann Zeta Function
| Tuning | Strength | Closest EDO | Integer limit | ||||
|---|---|---|---|---|---|---|---|
| ZPI (σ = 1) | Steps per octave | Step size (cents) | Height | EDO | Octave (cents) | Consistent | Distinct |
| 15zpi (σ = 1) | 6.95688550773 | 172.490980147 | 2.55384 | 7edo | 1207.43686103 | 6 | 5 |
| 26zpi (σ = 1) | 10.0089746115 | 119.892401228 | 2.57426 | 10edo | 1198.92401228 | 8 | 5 |
| 34zpi (σ = 1) | 12.0220488259 | 99.8165967700 | 2.85866 | 12edo | 1197.79916124 | 10 | 6 |
| 42zpi (σ = 1) | 13.9020220557 | 86.3183783764 | 2.50514 | 14edo | 1208.45729727 | 7 | 5 |
| 47zpi (σ = 1) | 15.0534708836 | 79.7158349246 | 2.69313 | 15edo | 1195.73752387 | 8 | 7 |
| 56zpi (σ = 1) | 17.0432556931 | 70.4090827252 | 2.65741 | 17edo | 1196.95440633 | 4 | 4 |
| 65zpi (σ = 1) | 18.9489976130 | 63.3278880767 | 3.02387 | 19edo | 1203.22987346 | 10 | 7 |
| 80zpi (σ = 1) | 22.0251749360 | 54.4831086920 | 2.99601 | 22edo | 1198.62839122 | 12 | 8 |
| 90zpi (σ = 1) | 24.0053572889 | 49.9888414723 | 2.82476 | 24edo | 1199.73219533 | 6 | 6 |
| 100zpi (σ = 1) | 25.9356337472 | 46.2683893402 | 2.71167 | 26edo | 1202.97812285 | 14 | 9 |
| 106zpi (σ = 1) | 27.0853383248 | 44.3044124320 | 2.90524 | 27edo | 1196.21913566 | 10 | 8 |
| 116zpi (σ = 1) | 28.9431579907 | 41.4605759463 | 2.68561 | 29edo | 1202.35670244 | 8 | 7 |
| 127zpi (σ = 1) | 30.9779815456 | 38.7371913897 | 3.23190 | 31edo | 1200.85293308 | 12 | 9 |
| 144zpi (σ = 1) | 34.0437506778 | 35.2487600839 | 3.07414 | 34edo | 1198.45784285 | 6 | 6 |
| 155zpi (σ = 1) | 35.9827898689 | 33.3492762616 | 2.80355 | 36edo | 1200.57394542 | 8 | 8 |
| 184zpi (σ = 1) | 40.9880790756 | 29.2768050385 | 3.32966 | 41edo | 1200.34900658 | 16 | 10 |
| 196zpi (σ = 1) | 43.0234004818 | 27.8917981043 | 2.78019 | 43edo | 1199.34731849 | 8 | 8 |
| 214zpi (σ = 1) | 46.0106419996 | 26.0809227572 | 3.25119 | 46edo | 1199.72244683 | 14 | 11 |
| 238zpi (σ = 1) | 49.9382924730 | 24.0296562132 | 2.90274 | 50edo | 1201.48281066 | 10 | 9 |
| 257zpi (σ = 1) | 52.9969882711 | 22.6427961125 | 3.46399 | 53edo | 1200.06819396 | 10 | 10 |
| 289zpi (σ = 1) | 58.0645692462 | 20.6666477609 | 3.25823 | 58edo | 1198.66557013 | 16 | 12 |
| 301zpi (σ = 1) | 59.9223835273 | 20.0259056693 | 2.98826 | 60edo | 1201.55434016 | 10 | 10 |
| 321zpi (σ = 1) | 63.0197888699 | 19.0416378969 | 2.87513 | 63edo | 1199.62318750 | 8 | 8 |
| 334zpi (σ = 1) | 65.0145858034 | 18.4573966776 | 3.23462 | 65edo | 1199.73078404 | 6 | 6 |
| 354zpi (σ = 1) | 68.0496579343 | 17.6341812204 | 3.14200 | 68edo | 1199.12432299 | 10 | 10 |
| 380zpi (σ = 1) | 71.9512656175 | 16.6779554147 | 3.61665 | 72edo | 1200.81278986 | 18 | 13 |
| 414zpi (σ = 1) | 76.9924672555 | 15.5859403235 | 3.28825 | 77edo | 1200.11740491 | 10 | 10 |
| 435zpi (σ = 1) | 80.0733926855 | 14.9862514845 | 3.14833 | 80edo | 1198.90011876 | 12 | 12 |
| 462zpi (σ = 1) | 83.9950884037 | 14.2865496400 | 3.19687 | 84edo | 1200.07016976 | 10 | 10 |
| 483zpi (σ = 1) | 87.0139579095 | 13.7908908965 | 3.44872 | 87edo | 1199.80750799 | 16 | 14 |
| 497zpi (σ = 1) | 89.0215260329 | 13.4798857476 | 3.02681 | 89edo | 1199.70983154 | 12 | 12 |
| 532zpi (σ = 1) | 93.9843698073 | 12.7680805059 | 3.39762 | 94edo | 1200.19956756 | 24 | 15 |
| 568zpi (σ = 1) | 99.0456175574 | 12.1156294402 | 3.56676 | 99edo | 1199.44731458 | 12 | 12 |
| 596zpi (σ = 1) | 102.936325452 | 11.6576922163 | 3.25007 | 103edo | 1200.74229828 | 15 | 15 |
| 655zpi (σ = 1) | 111.058159333 | 10.8051493669 | 3.39509 | 111edo | 1199.37157972 | 22 | 16 |
| 706zpi (σ = 1) | 117.971388652 | 10.1719579104 | 3.62695 | 118edo | 1200.29103343 | 12 | 12 |
| 796zpi (σ = 1) | 130.004267285 | 9.23046623824 | 3.72487 | 130edo | 1199.96061097 | 16 | 16 |
| 872zpi (σ = 1) | 139.992781938 | 8.57187051639 | 3.60746 | 140edo | 1200.06187229 | 10 | 10 |
| 965zpi (σ = 1) | 152.050659206 | 7.89210652729 | 3.68901 | 152edo | 1199.60019215 | 15 | 15 |
| 1114zpi (σ = 1) | 170.995049914 | 7.01774700849 | 3.82285 | 171edo | 1200.03473845 | 14 | 14 |
| 1210zpi (σ = 1) | 183.000273182 | 6.55736726036 | 3.76064 | 183edo | 1199.99820865 | 18 | 18 |
Notable Local Maxima of the Riemann Zeta Function after removing the prime 3 from the zeta product
| Tuning | Strength | Closest EDO | No-3 Integer limit | ||||
|---|---|---|---|---|---|---|---|
| No-3 ZPI analog | Steps per octave | Cents | Height | EDO | Octave | Consistent | Distinct |
| no-3 51zpi (σ = 1) | 15.9687074547 | 75.1469712502 | 2.56677 | 16edo | 1202.35154000 | 26 | 8 |
| no-3 75zpi (σ = 1) | 21.0417134383 | 57.0295762045 | 2.60042 | 21edo | 1197.62110029 | 17 | 10 |
| no-3 95zpi (σ = 1) | 24.9617781085 | 48.0734984016 | 2.64675 | 25edo | 1201.83746004 | 14 | 11 |
| no-3 127zpi (σ = 1) | 31.0146799866 | 38.6913552073 | 2.60405 | 31edo | 1199.43201143 | 11 | 11 |
| no-3 161zpi (σ = 1) | 37.0135086000 | 32.4205957606 | 2.92705 | 37edo | 1199.56204314 | 22 | 16 |
| no-3 196zpi (σ = 1) | 43.0494972034 | 27.8748900209 | 2.71380 | 43edo | 1198.62027090 | 22 | 19 |
| no-3 220zpi (σ = 1) | 47.0043385196 | 25.5295582875 | 2.69328 | 47edo | 1199.88923951 | 10 | 10 |
| no-3 276zpi (σ = 1) | 55.9891415481 | 21.4327272543 | 2.76321 | 56edo | 1200.23272624 | 20 | 19 |
| no-3 340zpi (σ = 1) | 65.9204029312 | 18.2037722259 | 2.65263 | 66edo | 1201.44896691 | 16 | 16 |
| no-3 354zpi (σ = 1) | 68.0229453080 | 17.6411061674 | 2.76285 | 68edo | 1199.59521939 | 11 | 11 |
| no-3 394zpi (σ = 1) | 74.0566473758 | 16.2038121158 | 2.76672 | 74edo | 1199.08209657 | 16 | 16 |
| no-3 421zpi (σ = 1) | 78.0097604150 | 15.3826904943 | 2.81219 | 78edo | 1199.84985856 | 17 | 16 |
| no-3 525zpi (σ = 1) | 93.0066513531 | 12.9023030347 | 2.97919 | 93edo | 1199.91418223 | 35 | 19 |
| no-3 751zpi (σ = 1) | 124.013627761 | 9.67635591079 | 3.13747 | 124edo | 1199.86813294 | 28 | 26 |
Notable Local Maxima of the Riemann Zeta Function after removing the prime 2 from the zeta product
| Tuning | Strength | Closest EDT | No-2 Integer limit | ||||
|---|---|---|---|---|---|---|---|
| No-2 ZPI (σ = 1) | Steps per octave | Cents | Height | EDT | Tritave | Consistent | Distinct |
| no-2 93zpi (σ = 1) | 24.5747239922 | 48.8306603314 | 2.12985 | 39edt | 1904.39575293 | 15 | 15 |
| no-2 151zpi (σ = 1) | 35.3061077059 | 33.9884534992 | 2.08576 | 56edt | 1903.35339595 | 15 | 15 |
| no-2 207zpi (σ = 1) | 44.8164999984 | 26.7758526445 | 2.10342 | 71edt | 1901.08553776 | 17 | 17 |
| no-2 222zpi (σ = 1) | 47.3516876312 | 25.3422857776 | 2.11876 | 75edt | 1900.67143332 | 15 | 15 |
| no-2 233zpi (σ = 1) | 49.1657210129 | 24.4072491012 | 2.07714 | 78edt | 1903.76542989 | 21 | 21 |
| no-2 273zpi (σ = 1) | 55.5359583782 | 21.6076220712 | 2.19450 | 88edt | 1901.47074227 | 11 | 11 |
| no-2 363zpi (σ = 1) | 69.4191721809 | 17.2862908372 | 2.08043 | 110edt | 1901.49199210 | 23 | 23 |
| no-2 380zpi (σ = 1) | 71.9200195089 | 16.6852012582 | 2.07565 | 114edt | 1902.11294344 | 17 | 17 |
| no-2 453zpi (σ = 1) | 82.6700405439 | 14.5155366092 | 2.38406 | 131edt | 1901.53529581 | 27 | 27 |
| no-2 492zpi (σ = 1) | 88.3238806401 | 13.5863595587 | 2.12238 | 140edt | 1902.09033822 | 9 | 9 |
| no-2 510zpi (σ = 1) | 90.8334979880 | 13.2109852266 | 2.23067 | 144edt | 1902.38187263 | 39 | 27 |
| no-2 550zpi (σ = 1) | 96.5187261015 | 12.4328205362 | 2.24293 | 153edt | 1902.22154203 | 15 | 15 |
| no-2 627zpi (σ = 1) | 107.244021785 | 11.1894348983 | 2.29774 | 170edt | 1902.20393272 | 15 | 15 |
| no-2 687zpi (σ = 1) | 115.412802617 | 10.3974600113 | 2.18983 | 183edt | 1902.73518207 | 15 | 15 |
| no-2 697zpi (σ = 1) | 116.734850378 | 10.2797064983 | 2.15793 | 185edt | 1901.74570218 | 29 | 29 |
| no-2 777zpi (σ = 1) | 127.486291223 | 9.41277676594 | 2.21095 | 202edt | 1901.38090672 | 17 | 17 |
| no-2 810zpi (σ = 1) | 131.822840677 | 9.10312654342 | 2.25360 | 209edt | 1902.55344758 | 21 | 21 |
| no-2 829zpi (σ = 1) | 134.373782790 | 8.93031345169 | 2.13475 | 213edt | 1902.15676521 | 29 | 29 |
| no-2 839zpi (σ = 1) | 135.657892938 | 8.84578091263 | 2.11125 | 215edt | 1901.84289622 | 15 | 15 |
| no-2 858zpi (σ = 1) | 138.196070465 | 8.68331491602 | 2.20051 | 219edt | 1901.64596661 | 11 | 11 |
| no-2 902zpi (σ = 1) | 143.873905513 | 8.34063686336 | 2.09948 | 228edt | 1901.66520485 | 11 | 11 |
| no-2 965zpi (σ = 1) | 152.075713777 | 7.89080629768 | 2.10893 | 241edt | 1901.68431774 | 15 | 15 |
| no-2 985zpi (σ = 1) | 154.604034485 | 7.76176381166 | 2.40811 | 245edt | 1901.63213386 | 21 | 21 |
| no-2 1029zpi (σ = 1) | 160.260260060 | 7.48782012177 | 2.17192 | 254edt | 1901.90631093 | 9 | 9 |
| no-2 1049zpi (σ = 1) | 162.750022676 | 7.37327086209 | 2.14738 | 258edt | 1902.30388242 | 17 | 17 |
| no-2 1069zpi (σ = 1) | 165.332187903 | 7.25811480039 | 2.19607 | 262edt | 1901.62607770 | 17 | 17 |
| no-2 1134zpi (σ = 1) | 173.506549648 | 6.91616542681 | 2.26764 | 275edt | 1901.94549237 | 29 | 29 |
| no-2 1159zpi (σ = 1) | 176.625850825 | 6.79402247404 | 2.14379 | 280edt | 1902.32629273 | 11 | 11 |
| no-2 1179zpi (σ = 1) | 179.167803205 | 6.69763193238 | 2.29964 | 284edt | 1902.12746880 | 15 | 15 |
| no-2 1245zpi (σ = 1) | 187.354933401 | 6.40495544056 | 2.28021 | 297edt | 1902.27176585 | 21 | 21 |
| no-2 1266zpi (σ = 1) | 189.909845446 | 6.31878772364 | 2.17116 | 301edt | 1901.95510482 | 17 | 17 |
| no-2 1297zpi (σ = 1) | 193.736743714 | 6.19397217583 | 2.12380 | 307edt | 1901.54945798 | 21 | 21 |
| no-2 1343zpi (σ = 1) | 199.415414525 | 6.01758897555 | 2.36503 | 316edt | 1901.55811627 | 39 | 39 |
Notable Local Maxima of the Riemann Zeta Function after removing the primes 2 and 3 from the zeta product
| Tuning | Strength | Closest ED5 | No-2 No-3 Integer limit | ||||
|---|---|---|---|---|---|---|---|
| No-2 No-3 ZPI analog | Steps per octave | Cents | Height | ED5 | Pentave | Consistent | Distinct |
| no-2 no-3 186zpi (σ = 1) | 41.3464998527 | 29.0230129340 | 1.75534 | 96ed5 | 2786.20924167 | 35 | 23 |
| no-2 no-3 565zpi (σ = 1) | 98.6253027359 | 12.1672630320 | 1.74188 | 229ed5 | 2786.30323433 | 29 | 29 |
| no-2 no-3 671zpi (σ = 1) | 113.258011095 | 10.5952769998 | 1.77217 | 263ed5 | 2786.55785095 | 19 | 19 |
| no-2 no-3 764zpi (σ = 1) | 125.745000550 | 9.54312294522 | 1.75634 | 292ed5 | 2786.59190001 | 37 | 37 |
| no-2 no-3 905zpi (σ = 1) | 144.297529480 | 8.31615069448 | 1.73926 | 335ed5 | 2785.91048265 | 43 | 41 |
| no-2 no-3 938zpi (σ = 1) | 148.562870929 | 8.07738833059 | 1.79949 | 345ed5 | 2786.69897405 | 25 | 25 |
| no-2 no-3 1046zpi (σ = 1) | 162.414291729 | 7.38851234841 | 1.73251 | 377ed5 | 2785.46915535 | 23 | 23 |
| no-2 no-3 1145zpi (σ = 1) | 174.880594782 | 6.86182478678 | 1.74084 | 406ed5 | 2785.90086343 | 25 | 25 |
| no-2 no-3 1196zpi (σ = 1) | 181.292147244 | 6.61915046096 | 1.77770 | 421ed5 | 2786.66234406 | 35 | 35 |
| no-2 no-3 1280zpi (σ = 1) | 191.632570168 | 6.26198353937 | 1.75036 | 445ed5 | 2786.58267502 | 29 | 29 |
The α–β–γ family
| Optimization | Equal division of a ratio | |||
|---|---|---|---|---|
| Proposed name | Steps per octave | Cents | Optimization method | |
| Alpha 3/1 | 1.90739592696007 | 629.130000247254 | Dave Benson | 3ed3/1 |
| Beta 3/1 | 3.14186231690763 | 381.939079106782 | Dave Benson | 5ed3/1 |
| Alpha 2/1 | 5.00991270509077 | 239.525131601721 | Dave Benson | 5ed2/1 |
| Gamma 3/1 | 5.04255621376059 | 237.974540913462 | Dave Benson | 8ed3/1 |
| Beta 2/1 | 6.99104980248710 | 171.648040552235 | Dave Benson | 7ed2/1 |
| Alpha 5/3 | 9.50583353877785 | 126.238272015258 | Dave Benson | 7ed5/3 |
| Gamma 2/1 | 11.9978480914311 | 100.017935787756 | Dave Benson | 12ed2/1 |
| Beta 5/3 | 12.2053823008782 | 98.3172808862904 | Dave Benson | 9ed5/3 |
| Alpha 3/2 | 15.3915238996928 | 77.9649895501219 | Dave Benson | 9ed3/2 |
| Beta 3/2 | 18.7990736394111 | 63.8329325698408 | Dave Benson | 11ed3/2 |
| Gamma 5/3 | 21.7094399215509 | 55.2754932571412 | Dave Benson | 16ed5/3 |
| Alpha 7/5 | 22.6653911133366 | 52.9441558718088 | Dave Benson | 11ed7/5 |
| Beta 7/5 | 26.7758951088566 | 44.8164289231577 | Dave Benson | 13ed7/5 |
| Alpha 4/3 | 31.3266790320926 | 38.3060074376432 | Dave Benson | 13ed4/3 |
| Gamma 3/2 | 34.1894540921914 | 35.0985422804417 | Dave Benson | 20ed3/2 |
| Beta 4/3 | 36.1372975038827 | 33.2066890135065 | Dave Benson | 15ed4/3 |
| Gamma 7/5 | 49.4404896216012 | 24.2716042900130 | Dave Benson | 24ed7/5 |
| Gamma 4/3 | 67.4633901646646 | 17.7874251067289 | Dave Benson | 28ed4/3 |
Unequal-step tunings
Unequal-step tunings from equal divisions of a ratio
| Tuning | Period | Mode | Why it matters |
|---|---|---|---|
| Stretched hemififth | 94\93<2/1> | 16 11 16 12 16 11 12 | |
| 833 Cent Acoustic Golden Scale [11] | 25\36<2/1> | 3 1 3 3 1 3 1 3 3 1 3 | |
| 833 Cent Logarithmic Golden Scale [8] | ϕ | ϕ 1 ϕ ϕ 1 ϕ 1 ϕ |