2.3.5.7.11.13.19.29 subgroup: Difference between revisions
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The '''2.3.5.7.11.13.19.29 subgroup''' (a.k.a. ''yazalathanatwena'' in [[color notation]], hereon referred to as ''the subgroup'') consists of [[just intonation]] [[interval]]s such that the highest [[prime factor]] in all [[ratio]]s is 29, but without 17 or 23. It is thus a subset of the [[29-limit]], or alternatively, it can be seen as the [[13-limit]] with extra primes [[19/1|19]] and [[29/1|29]], or the [[2.3.5.7.11.13.19 subgroup]] with 29 added in. | The '''2.3.5.7.11.13.19.29 subgroup''' (a.k.a. ''yazalathanatwena'' in [[color notation]], hereon referred to as ''the subgroup'') consists of [[just intonation]] [[interval]]s such that the highest [[prime factor]] in all [[ratio]]s is 29, but without 17 or 23. It is thus a subset of the [[29-limit]], or alternatively, it can be seen as the [[13-limit]] with extra primes [[19/1|19]] and [[29/1|29]], or the [[2.3.5.7.11.13.19 subgroup]] with 29 added in. | ||
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 | This subgroup is significant because it adds 19 as a counterpart of [[21/1|21]] in the 16::24 [[harmonics 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 a 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 == | ||