User:Lucius Chiaraviglio/Musical Mad Science: Difference between revisions

#  As the number of L intervals in a ''n''L 2s scale grows, the range of qualifying generator sizes shrinks, and so the scale becomes more brittle to tempering of the generator, and it becomes hard to find good ratios for specifying the generator.  Considering the wider of each pair of generators, the range of [[5L 2s]] (as in [[Meantone]], [[Superpyth]], and their relatives) is very wide range — you have to have a ''bad'' fifth to land outside of its range.  The range of [[7L 2s]] is still fairly wide, going from barely over [[52/35]] down to somewhat under [[81/55]]; [[9L 2s]] is narrower, going from barely over [[25/17]] down to somewhat under [[19/13]]; [[11L 2s]] ([[Ivan Wyschnegradsky]]'s original Diatonicized Chromatic scale) brackets [[16/11]]; and the ranges get progressively narrower and the ratios more complicated until by the time we get to 19L 2s, the range falls between two ratios, the second of which is not even all that simple:  [[13/9]] and [[36/25]].  The first is too sharp by somewhat over 1{{c}}, and the second is barely too flat; although since it is near-just as 10 steps of [[19edo]], which is equalized 19L 2s, we can count it as snapping to the lower end.  It is possible to come up with more complicated ratios by mediation between these slightly out-of-bounds endpoints, such as [[75/52]] and [[49/34]], or even [[62/43]] in the middle, but the latter uses unacceptably large primes, while the previous ratios and even 36/25 itself fail to map properly in the patent [[val]]s of some of the equal temperaments within the range of 17L 2s (this flaw of 36/25 making it tempting to use the slightly flatter [[23/16]], so before considering the next point, it seems better to specify the generator as a tempered 36/25 ~ 13/9, or perhaps even 23/16 ~ 13/9, either way with the proviso that the generator can never reach the just value of either endpoint without going out of range.  But the choice of generator tempering comma will need to depend upon which subgroup(s) counts as the core of this temperament, so let's not throw out any of the above intervals just yet. (More painstaking inspection has revealed that ~23/16 or ~13/9 are usable after all in significant parts of the tuning spectrum with only minimal use of warts, while ~62/43 is usable throughout again with only minimal use of warts — therefore this needs to be rewritten to prefer ~23/16 or ~13/9, with ~62/43 as a fallback, and the more complex sliding generator with the 53rd harmonic component only used as a last resort.)

Last modified:  [[User:Lucius Chiaraviglio|Lucius Chiaraviglio]] ([[User talk:Lucius Chiaraviglio|talk]]) 08:13, 26 April 2025 (UTC)

{{Harmonics in equal|19|intervals=odd|prec=2|columns=28|title=[[19edo]] (L=1, s=1, BrightGen is 10; patent ~13/9 = 10; patent ~62/43 = 10) — Equalized 17L 2s}}

{{Harmonics in equal|112|intervals=odd|prec=2|columns=28|title=[[112edo]] (L=6, s=5, BrightGen is 59; ''patent ~13/9 = 58; b val ~13/9 = 60''; patent ~62/43 = 59)}}

{{Harmonics in equal|93|intervals=odd|prec=2|columns=28|title=[[93edo]] (L=5, s=4, BrightGen is 49; ''patent ~13/9 = 50''; patent ~62/43 = 49)}}

{{Harmonics in equal|167|intervals=odd|prec=2|columns=28|title=[[167edo]] (L=9, s=7, BrightGen is 88; patent ~13/9 = 88; patent ~62/43 = 88)}}

{{Harmonics in equal|74|intervals=odd|prec=2|columns=28|title=[[74edo]] (L=4, s=3, BrightGen is 39; ''patent ~13/9 = 40''; patent ~13/9 = ; patent ~62/43 = 39) — Supersoft 17L 2s}}

{{Harmonics in equal|203|intervals=odd|prec=2|columns=28|title=[[203edo]] (L=11, s=8, BrightGen is 107; patent ~13/9 = 107; patent ~62/43 = 107)}}

{{Harmonics in equal|129|intervals=odd|prec=2|columns=28|title=[[129edo]] (L=7, s=5, BrightGen is 68; ''patent ~13/9 = 69''; patent ~62/43 = 68)}}

{{Harmonics in equal|184|intervals=odd|prec=2|columns=28|title=[[184edo]] (L=10, s=7, BrightGen is 97; patent ~13/9 = 97; patent ~62/43 = 97)}}

{{Harmonics in equal|55|intervals=odd|prec=2|columns=28|title=[[55edo]] (L=3, s=2, BrightGen is 29; ''patent ~13/9 = 30''; patent ~62/43 = 29) — Soft 17L 2s}}

{{Harmonics in equal|201|intervals=odd|prec=2|columns=28|title=[[201edo]] (L=11, s=7, BrightGen is 106; patent ~13/9 = 106; patent ~62/43 = 106)}}

{{Harmonics in equal|146|intervals=odd|prec=2|columns=28|title=[[146edo]] (L=8, s=5, BrightGen is 77; ''patent ~13/9 = 78''; patent ~62/43 = 77)}}

{{Harmonics in equal|237|intervals=odd|prec=2|columns=28|title=[[237edo]] (L=13, s=8, BrightGen is 125; patent ~13/9 = 125; patent ~62/43 = 125)}}

{{Harmonics in equal|91|intervals=odd|prec=2|columns=28|title=[[91edo]] (L=5, s=3, BrightGen is 48; ''patent ~13/9 = 49''; patent ~62/43 = 48) — Semisoft 17L 2s}}

{{Harmonics in equal|218|intervals=odd|prec=2|columns=28|title=[[218edo]] (L=12, s=7, BrightGen is 115; patent ~13/9 = 115; patent ~62/43 = 115)}}

{{Harmonics in equal|127|intervals=odd|prec=2|columns=28|title=[[127edo]] (L=7, s=4, BrightGen is 67; ''patent ~13/9 = 68''; patent ~62/43 = 67)}}

{{Harmonics in equal|163|intervals=odd|prec=2|columns=28|title=[[163edo]] (L=9, s=5, BrightGen is 86; ''patent ~13/9 = 87''; ''patent ~62/43 = 87 'k' wart usable'')}}

{{Harmonics in equal|36|intervals=odd|prec=2|columns=28|title=[[36edo]] (L=2, s=1, BrightGen is 19; patent ~13/9 = 19; patent ~62/43 = 19) — Basic 17L 2s}}

{{Harmonics in equal|161|intervals=odd|prec=2|columns=28|title=[[161edo]] (L=9, s=4, BrightGen is 85; ''patent ~13/9 = 86''; patent ~62/43 = 85)}}

{{Harmonics in equal|125|intervals=odd|prec=2|columns=28|title=[[125edo]] (L=7, s=3, BrightGen is 66; ''patent ~13/9 = 67, 'f' wart usable''; patent ~62/43 = 66)}}

{{Harmonics in equal|214|intervals=odd|prec=2|columns=28|title=[[214edo]] (L=12, s=5, BrightGen is 113; ''patent ~13/9 = 114''; patent ~62/43 = 113)}}

{{Harmonics in equal|89|intervals=odd|prec=2|columns=28|title=[[89edo]] (L=5, s=2, BrightGen is 47; patent ~13/9 = 47; patent ~62/43 = 47) — Semihard 17L 2s}}

{{Harmonics in equal|231|intervals=odd|prec=2|columns=28|title=[[231edo]] (L=13, s=5, BrightGen is 122; ''patent ~13/9 = 123''; patent ~62/43 = 122)}}

{{Harmonics in equal|142|intervals=odd|prec=2|columns=28|title=[[142edo]] (L=8, s=3, BrightGen is 75; patent ~13/9 = 75; ''patent ~62/43 = 74, 'k' wart usable'')}}

{{Harmonics in equal|195|intervals=odd|prec=2|columns=28|title=[[195edo]] (L=11, s=4, BrightGen is 103; ''patent ~13/9 = 104, 'f' wart usable if 'e' wart also used''; patent ~62/43 = 103)}}

{{Harmonics in equal|53|intervals=odd|prec=2|columns=28|title=[[53edo]] (L=3, s=1, BrightGen is 28; patent ~13/9 = 28; patent ~62/43 = 28) — Hard 17L 2s}}

{{Harmonics in equal|176|intervals=odd|prec=2|columns=28|title=[[176edo]] (L=10, s=3, BrightGen is 93; patent ~13/9 = 93; patent ~62/43 = 93)}}

{{Harmonics in equal|123|intervals=odd|prec=2|columns=28|title=[[123edo]] (L=7, s=2, BrightGen is 65; patent ~13/9 = 65; patent ~62/43 = 65)}}

{{Harmonics in equal|193|intervals=odd|prec=2|columns=28|title=[[193edo]] (L=11, s=3, BrightGen is 102; patent ~13/9 = 102; patent ~62/43 = 102)}}

{{Harmonics in equal|70|intervals=odd|prec=2|columns=28|title=[[70edo]] (L=4, s=1, BrightGen is 37; patent ~13/9 = 37; patent ~62/43 = 37) — Superhard 17L 2s}}

{{Harmonics in equal|157|intervals=odd|prec=2|columns=28|title=[[157edo]] (L=9, s=2, BrightGen is 83; patent ~13/9 = 83; patent ~62/43 = 83)}}

{{Harmonics in equal|87|intervals=odd|prec=2|columns=28|title=[[87edo]] (L=5, s=1, BrightGen is 46; patent ~13/9 = 46; patent ~62/43 = 46)}}

{{Harmonics in equal|104|intervals=odd|prec=2|columns=28|title=[[104edo]] (L=6, s=1, BrightGen is 55; patent ~13/9 = 55; patent ~62/43 = 55)}}

{{Harmonics in equal|17|intervals=odd|prec=2|columns=28|title=[[17edo]] (L=1, s=0, BrightGen is 9; patent ~13/9 = 9; patent ~62/43 = 9) — Collapsed 17L 2s}}

In detailed (but not complete) observations of scrolling through the above table group, I started noticing interesting things, like how the harmonic/subharmonics of the generator have unstable mapping (because no simple ratio with a reasonable sized numerator and denominator fits into this zone), but the 3rd harmonic is nearly rock-solid (and 112b is a respectable if overly-complex quarter-comma meantone approximation), although its mapping causes strange effects in the right-most column of the MOS spectrum table, causing ~13/9 to map to the bright generator in several EDOs in the soft half of the tuning spectrum and to map 1 step sharp of the bright generator in several EDOs in the hard half of the spectrum.  And the mapping of the 53rd harmonic is even more rock-solid as long as the right-most column of the tuning spectrum table is mostly left out (but it even works for the softer members of this column).  And there the 5th harmonic seems very much usable in the soft end of the scale tuning spectrum as long as the EDO sizes don't get too large (and even then, sometimes it is still okay), which looks to me like enabling a 2.3.5.23.53 meantone extension.  The 5th and 53rd harmonics go all over the place in the hard end, but there the 25th harmonic shines and is rock-solid as long as you don't go softer than 36edo (basic), and the 13th harmonic just barely misses being rock-solid in this zone (just barely breaks on 125edo, for which 125f would be not bad); in the soft half of the spectrum, the 13th harmonic always maps to 1 step too many for ~13/9 to be usable as the bright generator, and an 'f' wart would worsen consistency with nearby harmonics, except strangely in most of the right-most column of the tuning spectrum table.  Finally, the ratio ~62/43 (bright generator) or ~43/31 (dark generator) has amazing stability — even though the mapping of its component harmonics is pretty unstable, they co-vary sufficiently well that a wart is needed for proper mapping in only a few places, and in each case the wart does not appear to hurt consistency, at least at a brief inspection.

Last modified:  [[User:Lucius Chiaraviglio|Lucius Chiaraviglio]] ([[User talk:Lucius Chiaraviglio|talk]]) 08:13, 26 April 2025 (UTC)