2.3.5.7.11.13.19.29 subgroup: Difference between revisions
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This subgroup is a [[rank and codimension|rank-8]] system, and can be modeled in a 7-dimensional [[lattice]], with the primes [[3/1|3]], [[5/1|5]], [[7/1|7]], [[11/1|11]], [[13/1|13]], [[19/1|19]] and [[29/1|29]] represented by each dimension. The prime [[2/1|2]] does not appear in typical lattices because [[octave equivalence]] is presumed. If octave equivalence is not presumed, an eighth dimension is needed. | This subgroup is a [[rank and codimension|rank-8]] system, and can be modeled in a 7-dimensional [[lattice]], with the primes [[3/1|3]], [[5/1|5]], [[7/1|7]], [[11/1|11]], [[13/1|13]], [[19/1|19]] and [[29/1|29]] represented by each dimension. The prime [[2/1|2]] does not appear in typical lattices because [[octave equivalence]] is presumed. If octave equivalence is not presumed, an eighth dimension is needed. | ||
This subgroup is significant because it adds 19 as a counterpart of [[21/1|21]] in the 16::24 [[ | This subgroup is significant because it adds 19 as a counterpart of [[21/1|21]] in the 16::24 [[harmonic series segment]], so that any fifth-bounded chord involving 21 over the [[root]] has a harmonic (i.e. frequency-scale) inverse involving 19, and it adds 29 as a counterpart of [[27/1|27]] in 24::32, so that any fourth-bounded chord involving 27 over the root of 3 has a harmonic inverse involving 29. In addition, {19, 21} mirrors {27, 29} in 16::32, implying that any fifth-bounded chord involving 19 or 21 over the root has a fourth-bounded equivalent involving 27 or 29. 19/16 and 29/16 are close to a minor third and a supraminor seventh, respectively, so they can provide special "minor" flavors to [[otonal]] chords without clashing ''too'' much with the fundamental. Meanwhile, harmonics [[17/1|17]], [[23/1|23]], [[25/1|25]], and [[31/1|31]] may be considered to clash with the fundamental, being close to tonic and fifth when [[octave reduction|octave reduced]], so people may wish to exclude them. Therefore the subgroup can be considered to complete the harmonic series up to the fifth octave without the more difficult ones near the edges. | ||
== Regular temperaments == | == Regular temperaments == | ||
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{{Note|[[Wart notation]] is used to specify the [[val]] chosen for the edo. In the above list, "53j" means taking the second closest approximation of harmonic 29.}} | {{Note|[[Wart notation]] is used to specify the [[val]] chosen for the edo. In the above list, "53j" means taking the second closest approximation of harmonic 29.}} | ||
=== Rank-2 temperaments === | |||
[[Hemififths]], through the 41 & 58h extension, provides a fairly simple but efficient way to approach the subgroup through a dicot structure, finding ~19/16 and ~29/16 to be a pythagorean comma above ~7/6 and ~16/9 respectively, 29/16 here is approximated to within a cent of accuracy. | |||
[[Newt]] is arguably the most efficient rank-2 microtemperament of the subgroup despite its apparent great complexity, and much like hemififths, has a dicot structure. It has a strong extension for ~29/16, though its mapping is proportionally less accurate than the rest, being a cent off instead of tenths of a cent off. | |||
[[Cassandra]] provides a chain-of-fifths framework for approaching the subgroup, and has a very strong extension for 19/16 as a minor third, but has two plausible extensions for ~29/16: | |||
* 41 & 53 is simpler but less accurate, which equates it with ~9/5. | |||
* 41 & 94 is more accurate but more complex, which equates it with ~20/11. | |||
=== Rank-3 temperaments === | |||
[[Freyr]] detempers the hemififths extension and massively improves upon all primes in the subgroup, finding ~19/16 an aberschisma sharper except for ~29/16 which has the same mapping as hemififths but tuned less accurately because the fifth is closer to pure. | |||
[[Cassaschismic]] detempers cassandra by readily including 19/16 as a minor third plus an aberschisma with incredible accuracy. Coincidentally like cassandra, it has two plausible extensions for ~29/16: | |||
* 41 & 94 & 270 is simpler, with the same exact mapping as 41 & 94 but less accurately tuned because the fifth is sharper. | |||
* 41 & 53 & 270 is lower-badness, finding ~29/16 half a cent off as 2 aberschismas sharper than ~9/5 half a cent off pure. | |||
[[Category:Just intonation subgroups|#]] | [[Category:Just intonation subgroups|#]] | ||
[[Category:29-limit|#]] | [[Category:29-limit|#]] | ||