Hemimean clan: Difference between revisions
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Badness (Dirichlet): 0.195 | Badness (Dirichlet): 0.195 | ||
==== | ==== Tridecimal didacus ==== | ||
Tridecimal didacus (formerly ''roulette''; that name has now been reassigned to the no-threes 19-limit extension 37 & 68) is equivalent to [[hemiwur]] or [[grosstone]] with no mapping for prime 3. The mapping of prime 13 is somewhat strange, because it is the only mapping that requires a negative amount of generators (and a large amount of them), but it can be rationalized in a variety of ways, such as that because [[~]][[8/7]] is already tuned almost 3{{cent}} flat, it makes sense to equate two of it with [[~]][[13/10]] (tempering out the 8{{cent}} [[huntma]]). This mapping of 13 increases the [[badness]] of the temperament, but as it does not noticeably affect the optimal generators, it is usually a safe extension to didacus if prime 3 is not included. | |||
Subgroup: 2.5.7.11.13 | Subgroup: 2.5.7.11.13 | ||
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Badness (Dirichlet): 0.324 | Badness (Dirichlet): 0.324 | ||
==== Mediantone ==== | ===== Mediantone ===== | ||
Mediantone is named after its whole tone generator serving as the [[mediant]] of [[9/8]] and [[10/9]], namely [[19/17]], in addition to [[28/25]], as well as by the observation that this temperament seems to have been repeatedly rediscovered in parts in a variety of contexts, so that it seems to exist as a "median" of all of these temperaments' logics. It is also an intentional play on "[[meantone]]", as the context one is most likely to first discover this logic is when the tone also represents [[~]][[10/9]][[~]][[9/8]]. | Mediantone is named after its whole tone generator serving as the [[mediant]] of [[9/8]] and [[10/9]], namely [[19/17]], in addition to [[28/25]], as well as by the observation that this temperament seems to have been repeatedly rediscovered in parts in a variety of contexts, so that it seems to exist as a "median" of all of these temperaments' logics. It is also an intentional play on "[[meantone]]", as the context one is most likely to first discover this logic is when the tone also represents [[~]][[10/9]][[~]][[9/8]]. | ||
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Badness (Dirichlet): 0.612 | Badness (Dirichlet): 0.612 | ||
===== 2.5.7.11.13.17.19 subgroup ===== | ====== 2.5.7.11.13.17.19 subgroup ====== | ||
Subgroup: 2.5.7.11.13.17.19 | Subgroup: 2.5.7.11.13.17.19 | ||
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Badness (Dirichlet): 0.618 | Badness (Dirichlet): 0.618 | ||
===== Roulette ===== | |||
Roulette is an alternative no-twos 19-limit extension of tridecimal didacus to mediantone (the two mappings converging at [[37edo]]), equating (8/7)<sup>2</sup> to [[17/13]] in addition to 13/10, tempering out [[170/169]] and [[833/832]]; in doing so, it also tempers out the micro-comma [[2000033/2000000]] so that ([[50/49]])<sup>3</sup> is equated to [[17/16]]. The generator is then equated to 19/17 in the same way as in mediantone. | |||
Subgroup: 2.5.7.11.13.17 | |||
Comma list: [[170/169]], [[176/175]], [[640/637]], [[1375/1372]] | |||
Sval mapping: {{mapping| 1 2 2 2 5 7 | 0 2 5 9 -8 -18 }} | |||
: sval mapping generators: ~2, ~28/25 | |||
Optimal tuning (CWE): ~2 = 1\1, ~28/25 = 194.285 | |||
Optimal ET sequence: {{Optimal ET sequence| 6g, 31, 37, 68, 105 }} | |||
Badness (Dirichlet): 0.685 | |||
====== 2.5.7.11.13.17.19 subgroup ====== | |||
Subgroup: 2.5.7.11.13.17.19 | |||
Comma list: [[170/169]], [[176/175]], [[476/475]], [[640/637]], [[1375/1372]] | |||
Sval mapping: {{mapping| 1 2 2 2 5 7 7 | 0 2 5 9 -8 -18 -17 }} | |||
: sval mapping generators: ~2, ~28/25 | |||
Optimal tuning (CWE): ~2 = 1\1, ~19/17 = 194.259 | |||
Optimal ET sequence: {{Optimal ET sequence| 6g, 31, 37, 68, 105 }} | |||
Badness (Dirichlet): 0.676 | |||
=== Rectified hebrew === | === Rectified hebrew === | ||