Lemba: Difference between revisions

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m Mark golden ratio, where the MOS pattern holds perfectly no matter how many times you subdivide.
Line 1: Line 1:
'''Lemba''' (the name is from [[Herman Miller]]'s conlang name for the temperament) as a regular temperament is the intersection of the [[Jubilismic clan #Lemba|Jubilismic clan]] and the [[Gamelismic clan #Lemba|Gamelismic clan]]. This means that the perfect fifth is split into three equal parts, each approximately an [[8/7]]. It also means the period is half an octave, and repeats precisely a tritone apart, tempering out [[50/49]]. A generator plus a period comes very close to the [[golden ratio]] phi, which means ratios in the sequence 8:13:21:34:55 etc are also well approximated, and any one of these can be made just by choosing the right [[eigenmonzo]]. The combination of these factors means many composite ratios in the 2.3.5.7.13.17 subgroup are both well approximated and accessible with a relatively small gamut, giving you a strong selection of chords to choose from. It's main weaknesses are that ratios of 5 and 13 are conflated by the tempering out of [[65/64]], favoring 13 in the better tunings, so traditional major and minor chords are strongly neutral flavoured, and ratios involving 11 are not approximated at all until you have a large gamut. However, ignoring the 5 and 13, and focusing purely on the 2.3.7.17 subgroup, it can be highly accurate, with a total error of less than 7 cents in the tonality diamond in the least squares tuning. It forms mode of symmetry scales that are always double a fibonacci sequence number, at 4, 6, 10, 16, 26, etc, which means L/s ratios remain well mixed and clearly distinct many iterations down.
'''Lemba''' (the name is from [[Herman Miller]]'s conlang name for the temperament) as a regular temperament is the intersection of the [[Jubilismic clan #Lemba|Jubilismic clan]] and the [[Gamelismic clan #Lemba|Gamelismic clan]]. This means that the perfect fifth is split into three equal parts, each approximately an [[8/7]]. It also means the period is half an octave, and repeats precisely a tritone apart, tempering out [[50/49]]. A generator plus a period comes very close to the [[golden ratio]] phi, which means ratios in the sequence 8:13:21:34:55 etc are also well approximated, and any one of these can be made just by choosing the right [[eigenmonzo]]. The combination of these factors means many composite ratios in the 2.3.5.7.13.17 subgroup are both well approximated and accessible with a relatively small gamut, giving you a strong selection of chords to choose from. It's main weaknesses are that ratios of 5 and 13 are conflated by the tempering out of [[65/64]], favoring 13 in the better tunings, so traditional major and minor chords are strongly neutral flavoured, and ratios involving 11 are not approximated at all until you have a large gamut. However, ignoring the 5 and 13, and focusing purely on the 2.3.7.17 subgroup, it can be highly accurate, with a total error of less than 7 cents in the tonality diamond in the least squares tuning. It forms mode of symmetry scales that are always double a fibonacci sequence number, at 4, 6, 10, 16, 26, etc, which means L/s ratios remain well mixed and clearly distinct many iterations down.


==Spectrum of Lemba Tunings by Eigenmonzos==
== Spectrum of Lemba Tunings by Eigenmonzos ==


Gencom: [7/5 8/7; 45/44 50/49 65/64 78/77]
Gencom: [7/5 8/7; 45/44 50/49 65/64 78/77]
Line 7: Line 7:
Gencom map: [<2 2 5 6 5 7|,[<0 3 -1 -1 5 1|]
Gencom map: [<2 2 5 6 5 7|,[<0 3 -1 -1 5 1|]


{| class="wikitable"
{| class="wikitable center-1 right-2"
|-
|-
! Eigenmonzo
! Eigenmonzo
! Supermajor Second
! Supermajor Second
! Comments
|-
|-
| 5/4
| 5/4
| 213.686
| 213.686
|
|-
|-
| 15/11
| 15/11
| 221.016
| 221.016
|
|-
|-
| 12/11
| 12/11
| 224.681
| 224.681
|
|-
|-
| 3\16
| 3\16
| 225.000
| 225.000
|
|-
|-
| 13/10
| 13/10
| 227.107
| 227.107
|
|-
|-
| 11/10
| 11/10
| 227.501
| 227.501
|
|-
|-
| 13/11
| 13/11
| 227.698
| 227.698
|
|-
|-
| 8\42b
| 8\42b
| 228.571
| 228.571
|
|-
|-
| 6/5
| 6/5
| 228.910
| 228.910
|
|-
|-
| (2-Φ)x600
| (2-Φ)x600
| 229.179 (Golden Lemba. L/s ratios are always precisely Φ, and MOS scales are always precisely 2xΦ)
| 229.179
| Golden Lemba. L/s ratios are always precisely Φ, and MOS scales are always precisely 2xΦ
|-
|-
| 21/13
| 21/13
| 230.253
| 230.253
|
|-
|-
| 11/8
| 11/8
| 230.264
| 230.264
|
|-
|-
| 14/11
| 14/11
| 230.415 (15 limit minimax)
| 230.415
| 15 limit minimax
|-
|-
| 13/12
| 13/12
| 230.714
| 230.714
|
|-
|-
| 5\26
| 5\26
| 230.769
| 230.769
|
|-
|-
| 10/9
| 10/9
| 231.085 (9, 11 and 13 limit minimax)
| 231.085
| 9, 11 and 13 limit minimax
|-
|-
| 8/7
| 8/7
| 231.174 (7 limit minimax)
| 231.174
| 7 limit minimax
|-
|-
| [0 63 -20 -20 22 -6>
| [0 63 -20 -20 22 -6>
| 231.250 (13 limit least squares)
| 231.250
| 13 limit least squares
|-
|-
| [0 17 -6 -6 6>
| [0 17 -6 -6 6>
| 231.294 (11 limit least squares)
| 231.294
| 11 limit least squares
|-
|-
| 52521875/177147
| 52521875/177147
| 231.298 (7 limit least squares)
| 231.298
| 7 limit least squares
|-
|-
| [0 66 -17 -23 25 -7>
| [0 66 -17 -23 25 -7>
| 231.399 (15 limit least squares)
| 231.399
| 15 limit least squares
|-
|-
| 17/13
| 17/13
| 232.213
| 232.213
|
|-
|-
| 12\62
| 12\62
| 232.258
| 232.258
|
|-
|-
| 129140163/1500625
| 129140163/1500625
| 232.418 (9 limit least squares)
| 232.418
| 9 limit least squares
|-
|-
| 18/13
| 18/13
| 232.676
| 232.676
|
|-
|-
| Φ
| Φ
| 233.090
| 233.090
|
|-
|-
| 7/6
| 7/6
| 233.282
| 233.282
|
|-
|-
| 7\36
| 7\36
| 233.333
| 233.333
|
|-
|-
| 9/7
| 9/7
| 233.583
| 233.583
|
|-
|-
| 4/3
| 4/3
| 233.985
| 233.985
|
|-
|-
| 21/17
| 21/17
| 234.274
| 234.274
|
|-
|-
|  
|  
| 234.485 (2.3.7.17 subgroup least squares)
| 234.485
| 2.3.7.17 subgroup least squares
|-
|-
| 9\46
| 9\46
| 234.783
| 234.783
|
|-
|-
| 17/16
| 17/16
| 234.985
| 234.985
|
|-
|-
| 21/16
| 21/16
| 235.390
| 235.390
|
|-
|-
| 11\56
| 11\56
| 235.714
| 235.714
|
|-
|-
| 14/13
| 14/13
| 235.851
| 235.851
|
|-
|-
| 11/9
| 11/9
| 236.851
| 236.851
|
|-
|-
| 16/15
| 16/15
| 237.243
| 237.243
|
|-
|-
| 15/14
| 15/14
| 239.814
| 239.814
|
|-
|-
| 16/13
| 16/13
| 240.528
| 240.528
|
|-
|-
| 15/13
| 15/13
| 247.741
| 247.741
|
|}
|}