Lemba: Difference between revisions
m Mark golden ratio, where the MOS pattern holds perfectly no matter how many times you subdivide. |
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'''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 | | 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 | | 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 | | 231.085 | ||
| 9, 11 and 13 limit minimax | |||
|- | |- | ||
| 8/7 | | 8/7 | ||
| 231.174 | | 231.174 | ||
| 7 limit minimax | |||
|- | |- | ||
| [0 63 -20 -20 22 -6> | | [0 63 -20 -20 22 -6> | ||
| 231.250 | | 231.250 | ||
| 13 limit least squares | |||
|- | |- | ||
| [0 17 -6 -6 6> | | [0 17 -6 -6 6> | ||
| 231.294 | | 231.294 | ||
| 11 limit least squares | |||
|- | |- | ||
| 52521875/177147 | | 52521875/177147 | ||
| 231.298 | | 231.298 | ||
| 7 limit least squares | |||
|- | |- | ||
| [0 66 -17 -23 25 -7> | | [0 66 -17 -23 25 -7> | ||
| 231.399 | | 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 | | 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 | | 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 | ||
| | |||
|} | |} | ||