No-twos subgroup temperaments

Revision as of 06:06, 23 August 2024 by Lériendil (talk | contribs) (Polaris)

(WIP, catalog of 3.5.7 subgroup rank two temperaments will eventually be redirected here)

This is a collection of subgroup temperaments which omit the prime harmonic of 2. Because of the absence of octaves, these are all nonoctave scales using a period of a tritave, or if harmonic 3 is also excluded, 5/1.

Overview by mapping of 5

Classified by focusing on the mapping of 5th harmonic, similar to Rank-2 temperaments by mapping of 3.

  • Arcturus, Aldebaran and Polaris are with 3/1 period and ~5/3 generator. There is one-to-one correspondence between 3.5 subgroup and mapped intervals.
  • BPS is with a ~9/7 generator, two of which give the ~5/3.
  • Sirius is with a ~25/21 generator, three of which give the ~5/3.
  • Deneb is with a ~11/9 generator, three of which give the ~9/5.
  • Canopus is with a ~7/5 generator, five of which give the ~27/5 (9/5 up a tritave).
  • Alnilam is with a ~81/55 generator, ten of which give the ~243/5 (9/5 up three tritaves).
  • Izar is with a ~16807/10125 generator, twelve of which give the ~2187/5 (9/5 up five tritaves).
  • Mintaka does not include the 5th harmonic, and has an ~11/7 generator, two of which give the ~27/11, and three of which give the ~27/7 (9/7 and a tritave).

3.5.7 subgroup temperaments

Arcturus

see Arcturus, Arcturus clan

Subgroup: 3.5.7

Comma list: 15625/15309

Sval mapping: [1 0 -7], 0 1 6]]

Sval mapping generators: ~3, ~5

POTE generator: ~5/3 = 878.042

Optimal ET sequence: b2, b11, b13

BPS

see Bohlen-Pierce-Stearns

Subgroup: 3.5.7

Comma list: 245/243

Sval mapping: [1 1 2], 0 -2 1]]

Sval mapping generators: ~3, ~9/7

Optimal tuning (POTE): ~3 = 1\1edt, ~9/7 = 440.4881

Optimal ET sequence: b4, b9, b13, b56, b69, b82, b95

Canopus

see Canopus

Subgroup: 3.5.7

Comma list: 16875/16807

Subgroup-val mapping[1 3 3], 0 -5 -4]]

Sval mapping generators: ~3, ~7/5

Optimal tuning (CTE): ~3 = 1\1edt, ~7/5 = 584.017

Supporting ETs: b13, b10, b75, b62, b23, b49, b36, b16, b7cd, 29, b42c, b19cd, b33cd, b55c

Izar

Subgroup: 3.5.7

Comma list: 13841287201/13839609375

Subgroup-val mapping[1 7 5], 0 -12 -7]]

Sval mapping generators: ~3, ~16807/10125

Optimal tuning (CTE): ~3 = 1\1edt, ~16807/10125 = 877.280

Supporting ETs: b13, b11cd, b193, b15cd, b180, b24c, b167, b37c, b154, 141, b50c, b28cd, b128, b63c

3.5.11 subgroup temperaments

Polaris

see Polaris

Polaris tempers out the comma 177147/171875, and thus equates 7 5/3's with 15/11, or equivalently 7 9/5's with 11/9.

Subgroup: 3.5.11

Comma list: 177147/171875

Gencom: [3/1 5/3; 177147/171875]

Mapping: [1 2 1], 0 1 -6]]

POTE generator: ~5/3 = 892.6

EDTs: 17, 15, 32, 49, 13[+11], 47, 19, 11[+11], 81, 66, 79[+11], 62[+11], 28[+11], 21[-11]

Deneb

see Deneb

Subgroup: 3.5.11

Comma list: 6655/6561

Gencom: [3/1 11/9; 6655/6561]

Mapping: [1 2 2], 0 -3 1]]

POTE generator: ~11/9 = 340.242

EDTs: 28, 11, 17, 6, 39, 5, 67, 45, 50, 16, 23, 73, 61, 62

Alnilam

Effectively a microtemperament, Alnilam takes a generator of an 81/55 flat fifth and equates 9 of them with 11/9. The name was given by CompactStar to continue with the theme of naming no-twos temperaments after proper star names, but also to indirectly reference mavila.

Subgroup: 3.5.11

Comma list: [0 -35 9 0 10

Gencom: [3/1 81/55; [0 -35 9 0 10]

Mapping: [[1 5 -1], 0 -10 9]]

CTE generator: ~81/55 = 672.410

EDTs: 99, 17, 82, 116, 181, 65, 14[-5], 280, 48, 215, 31, 133, 314, 263

Other tritave-based subgroups

Aldebaran

Subgroup: 3.5.13

Comma list: 3159/3125

Mapping: [1 0 5], 0 1 -2]]

Supporting ETs: 15, 17, 13, 32, 47, 28, 11[-13], 19[+13], 43, 9[-13], 7[-13], 49[+13], 21[+13], 41[-13]

CTE generator: ~5/3 = 887.76

Mintaka

see Mintaka

Subgroup: 3.7.11

Comma list: 1331/1323

Sval mapping: [1 0 1], 0 3 2]]

Sval mapping generators: ~3, ~21/11

Optimal tunings:

  • PEWE (Pure-Equaves WE): ~3 = 1\1ed3, ~11/7 = 778.961
  • CWE: ~3 = 1\1ed3, ~11/7 = 778.803

Supporting ETs: b22, b5, b17, b39, b12, b61, b27, b7, b83, b49, b56, b32, b29, b100

No-twos-or-threes subgroup temperaments

Antipyth

see Antipyth

Subgroup: 5.7.11

Comma list: 859375/823543

Subgroup-val mapping[1 2 7], 0 1 7]]

Mapping generators: ~5, ~7/25

Optimal tuning (CTE): ~5 = 1\1ed5, ~7/5 = 592.728

Supporting ETs: c14, c5, c19, c33, c47, c9e, c61, c75, c23e, c24e, c52e, c80e, c89e, c37e

Juggernaut

see Juggernaut

Subgroup: 5.7.11

Comma list: 125/121

Subgroup-val mapping[2 4 3], 0 1 0]]

Mapping generators: ~11/5, ~7/25

Optimal tuning (CTE): ~11/5 = 1\2ed5, ~7/5 = 582.512

Supporting ETs: c14, c10, c6, c18, c24, c22, c32, c16, c38, c8d, c34, c26d, c46, c52e

Tridecimal Juggernaut

Subgroup: 5.7.11.13

Comma list: 125/121, 637/625

Subgroup-val mapping[2 4 3 0], 0 1 0 -2]]

Mapping generators: ~11/5, ~7/25

Optimal tuning (CTE): ~11/5 = 1\2ed5, ~7/5 = 582.512

Supporting ETs: c10, c14, c6, c24, c34, c16f, c44, c18f, c38, c26f, c54, c64

Graphs

 
Complexity vs. damage plot. z<1 corresponds to the "Middle Path" inclusion criterion.

Projective tuning space diagrams

 
Temperaments with smaller commas, labeled by name
 
Temperaments with smaller commas, labeled by comma
 
Temperaments with larger commas, labeled by name
 
Temperaments with larger commas, labeled by comma
 
Both sets, labeled by name
 
Both sets, labeled by comma

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