Hemimage temperaments: Difference between revisions

This is a collection of [[rank-2 temperament|rank-2]] [[temperament]]s [[tempering out]] the [[hemimage comma]] ({{monzo|legend=1| 5 -7 -1 3 }}, [[ratio]]: 10976/10935).

* [[Quasisuper]] (+64/63) → [[Archytas clan #Quasisuper|Archytas clan]]

* ''[[Liese]]'' (+81/80) → [[Meantone family #Liese|Meantone family]]

* ''[[Pluto]]'' (+4000/3969) → [[Octagar temperaments #Pluto|Octagar temperaments]]

* ''[[Unicorn]]'' (+126/125) → [[Unicorn family #Septimal unicorn|Unicorn family]]

Considered below are degrees, bicommatic, bisupermajor, squarschmidt, and leapmonth, in the order of increasing [[badness]].  

: ''For the 5-limit version, see [[Very high accuracy temperaments #Kwazy]].''

 

[[Subgroup]]: 2.3.5.7

[[Comma list]]: 10976/10935, 65625/65536

{{Mapping|legend=1| 2 1 6 1 | 0 8 -5 17 }}

[[Optimal tuning]]s:  

* [[CWE]]: ~1225/864 = 600.0000{{c}}, ~192/175 = 162.8082{{c}}

: error map: {{val| 0.000 +0.510 -0.355 -1.087 }}

{{Optimal ET sequence|legend=1| 22, 74d, 96d, 118, 140, 258, 398, 656d }}

[[Badness]] (Sintel): 1.66

Comma list: 385/384, 3388/3375, 9801/9800

Mapping: {{mapping| 2 1 6 1 8 | 0 8 -5 17 -4 }}

Optimal tunings:  

* CWE: ~99/70 = 600.0000{{c}}, ~11/10 = 162.7788{{c}}

{{Optimal ET sequence|legend=0| 22, 74d, 96d, 118, 258e, 376de, 634dee }}

Badness (Sintel): 1.06

== Bicommatic ==

Used to be known simply as the ''commatic'' temperament, the bicommatic temperament has a period of half octave and a generator of 20.4 cents, a small interval ("commatic") which represents 81/80, 99/98, and 100/99 all tempered together.

[[Subgroup]]: 2.3.5.7

[[Comma list]]: 10976/10935, 50421/50000

{{Mapping|legend=1| 2 3 4 5 | 0 5 19 18 }}

[[Optimal tuning]]s:  

* [[CWE]]: ~567/400 = 600.0000{{c}}, ~81/80 = 20.3837{{c}}

: error map: {{val| 0.000 -0.037 +0.976 -1.920 }}

{{Optimal ET sequence|legend=1| 58, 118, 294, 412d }}

[[Badness]] (Sintel): 2.13

Comma list: 441/440, 3388/3375, 8019/8000

Mapping: {{mapping| 2 3 4 5 6 | 0 5 19 18 27 }}

Optimal tunings:  

* CWE: ~99/70 = 600.0000{{c}}, ~81/80 = 20.3948{{c}}

{{Optimal ET sequence|legend=0| 58, 118, 294, 412d }}

Badness (Sintel): 1.01

=== 13-limit ===

Comma list: 196/195, 352/351, 729/728, 1001/1000

Mapping: {{mapping| 2 3 4 5 6 7 | 0 5 19 18 27 12 }}

Optimal tunings:  

* CWE: ~99/70 = 600.0000{{c}}, ~66/65 = 20.4093{{c}}

{{Optimal ET sequence|legend=0| 58, 118, 176f }}

Badness (Sintel): 1.09

=== 17-limit ===

Comma list: 170/169, 196/195, 289/288, 352/351, 561/560

Mapping: {{mapping| 2 3 4 5 6 7 8 | 0 5 19 18 27 12 5 }}

Optimal tunings:  

* CWE: ~17/12 = 600.0000{{c}}, ~66/65 = 20.3804{{c}}

{{Optimal ET sequence|legend=0| 58, 118 }}

Badness (Sintel): 1.14

== Degrees ==

{{About|the regular temperament|scale degrees|degree}}

{{See also| 20th-octave temperaments }}

Degrees temperament has a period of 1/20 octave and tempers out the hemimage (10976/10935) and the dimcomp (390625/388962). In this temperament, one period equals ~28/27, two equals ~15/14, three equals ~10/9, five equals ~25/21, six equals ~16/13, seven equals ~14/11, nine equals ~15/11, and ten equals ~99/70.  

An obvious extension to the 23-limit exists by mapping [[23/20]] to 4\20 (1\5), [[69/56]] to 6\20 (3\10), and [[23/18]] to 7\20. By observing that 1\20 works as [[30/29]]~[[29/28]]~[[28/27]], with 29/28 being especially accurate, and by mapping [[29/22]] to 2\5, we get a uniquely elegant extension to the 29-limit which tempers out [[726/725]], which is the difference between [[33/25]] and [[29/22]], as well as [[784/783]] ({{S|28}}) and [[841/840]] ({{S|29}}). An edo as large as [[220edo|220]] supports it by patent val, though it does not appear in the optimal ET sequence, and [[80edo]] and [[140edo]] are both much more recommendable tunings.

By equating [[37/28]] with 2\5 and more accurately [[85/74]] with 1\5 and [[44/37]] with 1\4 (among many other equivalences), we get an extension for prime [[37/1|37]] agreeing with many [[semiconvergent]]s, tempering out [[481/480]]. By mapping [[60/41]] and [[41/28]] to 11\20 or equivalently [[56/41]] and [[41/30]] to 9\20 and by mapping [[44/41]] to 1\10 (among many other equivalences), there is a very efficient extension for prime [[41/1|41]] tempering out [[451/450]].

The 80-note generator chain is ideal, so [[80edo]] is in some sense both a trivial and maximally efficient tuning of this temperament. We also observe an abundance of JI interpretations of [[20edo]] by combining primes so that all things require 3 generators, yielding: 37:44:54:56:58:60:69:74:82:85. Alternatively, combining primes so that all things require 2 generators yields 36:40:46:51 which except for intervals of 51 is contained implicitly in the above. The ratios therein should thus be instructive for how the structure of 20edo relates to its representation of JI in this temperament. Note that prime 47 can be added but only really makes sense in rooted form in [[140edo]].

[[Subgroup]]: 2.3.5.7

{{Mapping|legend=1| 20 0 -17 -39 | 0 1 2 3 }}

: [[error map]]: {{val| -0.157 +0.812 -0.647 -0.220 }}

* [[CWE]]: ~28/27 = 60.0000{{c}}, ~3/2 = 702.9324{{c}} (~126/125 = 17.0676{{c}})

: error map: {{val| 0.000 +0.977 -0.449 -0.029 }}

{{Optimal ET sequence|legend=1| 60, 80, 140, 640b, 780b }}

[[Badness]] (Sintel): 2.69

Mapping: {{mapping| 20 0 -17 -39 -26 | 0 1 2 3 3 }}

* WE: ~28/27 = 59.9929{{c}}, ~3/2 = 703.1478{{c}} (~100/99 = 16.7666{{c}})

{{Optimal ET sequence|legend=0| 60e, 80, 140, 360 }}

Badness (Sintel): 1.55

Mapping: {{mapping| 20 0 -17 -39 -26 74 | 0 1 2 3 3 0 }}

* WE: ~28/27 = 59.9996{{c}}, ~3/2 = 703.0749{{c}} (~100/99 = 16.9197{{c}})

{{Optimal ET sequence|legend=0| 60e, 80, 140 }}

Badness (Sintel): 1.35

=== 17-limit ===

Subgroup: 2.3.5.7.11.13.17

Comma list: 289/288, 325/324, 352/351, 561/560, 1001/1000

Mapping: {{mapping| 20 0 -17 -39 -26 74 50 | 0 1 2 3 3 0 1 }}

* WE: ~28/27 = 60.0058{{c}}, ~3/2 = 703.0364{{c}} (~100/99 = 17.0335{{c}})

* CWE: ~28/27 = 60.0000{{c}}, ~3/2 = 703.0061{{c}} (~100/99 = 16.9939{{c}})

{{Optimal ET sequence|legend=0| 60e, 80, 140 }}

Badness (Sintel): 1.17

=== 19-limit ===

Subgroup: 2.3.5.7.11.13.17.19

Comma list: 286/285, 289/288, 325/324, 352/351, 400/399, 476/475

Mapping: {{mapping| 20 0 -17 -39 -26 74 50 85 | 0 1 2 3 3 0 1 0 }}

Optimal tunings:  

* WE: ~28/27 = 59.9961{{c}}, ~3/2 = 703.1523{{c}} (~100/99 = 16.8015{{c}})

* CWE: ~28/27 = 60.0000{{c}}, ~3/2 = 703.1777{{c}} (~100/99 = 16.8223{{c}})

{{Optimal ET sequence|legend=0| 60e, 80, 140 }}

Badness (Sintel): 1.27

Subgroup: 2.3.5.7.11.13.17.19.23

Comma list: 253/252, 286/285, 289/288, 325/324, 352/351, 391/390, 400/399

Mapping: {{mapping| 20 0 -17 -39 -26 74 50 85 27 | 0 1 2 3 3 0 1 0 2 }}

Optimal tunings:  

* WE: ~28/27 = 59.9990{{c}}, ~3/2 = 703.1804{{c}} (~100/99 = 16.8074{{c}})

* CWE: ~28/27 = 60.0000{{c}}, ~3/2 = 703.1870{{c}} (~100/99 = 16.8130{{c}})

{{Optimal ET sequence|legend=0| 60e, 80, 140 }}

Subgroup: 2.3.5.7.11.13.17.19.23.29

Comma list: 253/252, 286/285, 289/288, 325/324, 352/351, 391/390, 400/399, 406/405

Mapping: {{mapping| 20 0 -17 -39 -26 74 50 85 27 2 | 0 1 2 3 3 0 1 0 2 3 }}

* CWE: ~29/28 = 60.0000{{c}}, ~3/2 = 703.1891{{c}} (~100/99 = 16.8109{{c}})

{{Optimal ET sequence|legend=0| 60e, 80, 140 }}

Badness (Sintel): 1.13

: ''For the 5-limit version, see [[Father–3 equivalence continuum #Squarschmidt (5-limit)]].''

Squarschimidt may be described as {{nowrap| 118 & 121 }} temperament. The extension here is a less accurate 7-limit interpretation, tempering out the hemimage comma and quasiorwellisma, [[29360128/29296875]]. In the [[11-limit]], it tempers out [[3025/3024]], [[5632/5625]], and [[12005/11979]], and the generator represents [[~]][[44/35]].  

[[Subgroup]]: 2.3.5.7

[[Comma list]]: 10976/10935, 29360128/29296875

{{Mapping|legend=1| 1 -8 1 -20 | 0 29 4 69 }}

* [[WE]]: ~2 = 1199.9006{{c}}, ~1125/896 = 396.6104{{c}}

: [[error map]]: {{val| -0.099 +0.543 +0.029 -0.719 }}

: error map: {{val| 0.000 +0.653 +0.253 -0.552 }}

{{Optimal ET sequence|legend=1| 118, 239, 357, 596 }}

[[Badness]] (Sintel): 3.36

Comma list: 3025/3024, 5632/5625, 10976/10935

Mapping: {{mapping| 1 -8 1 -20 -21 | 0 29 4 69 74 }}

* WE: ~2 = 1199.9005{{c}}, ~44/35 = 396.6107{{c}}

* CWE: ~2 = 1200.0000{{c}}, ~44/35 = 396.6419{{c}}

{{Optimal ET sequence|legend=0| 118, 239, 357, 596 }}

Badness (Sintel): 1.26

== Leapmonth ==

Leapmonth may be described as the {{nowrap| 63 & 80 }} temperament, generated by a [[3/2|perfect fifth]] and being a strong extension of [[leapfrog]]. It was named by [[Flora Canou]] in 2025 following the pattern demonstrated by ''leapday'' and ''leapweek'', the two simpler extensions of leapfrog.  

[[Subgroup]]: 2.3.5.7

[[Comma list]]: 10976/10935, 51200/50421

{{Mapping|legend=1| 1 0 -58 -21 | 0 1 38 15 }}

[[Optimal tuning]]s:  

* [[WE]]: ~2 = 1198.8005{{c}}, ~3/2 = 704.2543{{c}}

: [[error map]]: {{val| -1.200 +1.100 -0.659 +2.186 }}

* [[CWE]]: ~2 = 1200.0000{{c}}, ~3/2 = 704.9318{{c}}

: error map: {{val| 0.000 +2.977 +1.093 +5.150 }}

[[Badness]] (Sintel): 4.79

Subgroup: 2.3.5.7.11

Comma list: 540/539, 896/891, 1331/1323

Mapping: {{mapping| 1 0 -58 -21 -14 | 0 1 38 15 11 }}

* WE: ~2 = 1198.8679{{c}}, ~3/2 = 704.2911{{c}}

* CWE: ~2 = 1200.0000{{c}}, ~3/2 = 704.9318{{c}}

{{Optimal ET sequence|legend=0| 17c, 46c, 63, 80, 223bde, 303bdde }}

Badness (Sintel): 1.88

=== 13-limit ===

Subgroup: 2.3.5.7.11.13

Comma list: 169/168, 352/351, 364/363, 540/539

Mapping: {{mapping| 1 0 -58 -21 -14 -1 | 0 1 38 15 11 8 }}

Optimal tunings:  

* CWE: ~2 = 1200.0000{{c}}, ~3/2 = 704.9218{{c}}

{{Optimal ET sequence|legend=0| 17c, 46c, 63, 80, 143d }}

Badness (Sintel): 1.53

[[Category:Hemimage temperaments| ]] <!-- main article -->