7L 1s: Difference between revisions
→Theory: cleanup |
ArrowHead294 (talk | contribs) mNo edit summary |
||
| Line 7: | Line 7: | ||
{{MOS scale properties}} | {{MOS scale properties}} | ||
=== Proposed names === | |||
Mode names are from [[Porcupine Temperament Modal Harmony|Porcupine temperament modal harmony]]. Descriptive mode names are based on using 1 | Mode names are from [[Porcupine Temperament Modal Harmony|Porcupine temperament modal harmony]]. Descriptive mode names are based on using {{dash|1, 4, 7}}, i.e. 3+3 triads as a basis for harmony. | ||
{| | {{MOS modes | ||
| Mode names = | |||
octopus $ | |||
mantis $ | |||
dolphin $ | |||
crab $ | |||
tuna $ | |||
| | salmon $ | ||
| | starfish $ | ||
whale $ | |||
| Table Headers=Name Origin | |||
| Table Entries= | |||
Bright quartal $ | |||
Dark quartal $ | |||
Bright major $ | |||
Middle major $ | |||
Dark major $ | |||
Bright minor $ | |||
Middle minor $ | |||
Dark minor $ | |||
}} | |||
== Theory == | == Theory == | ||
=== Low harmonic entropy scales === | === Low harmonic entropy scales === | ||
There are three notable [[harmonic entropy]] minima with this [[mos]] pattern. The lowest accuracy one is [[porcupine]], in which two generators make a [[6/5]] and three make a [[4/3]]. The range of porcupine tunings is about 2\15 to 3\22. Less well-known and more accurate is [[greeley]], in which two generators are still 6/5 but three fall quite short of a 4/3, but the scale happens to closely approximate a lot of higher-complexity intervals like [[10/7]], [[11/7]], etc. Thirdly and finally, [[tempering out]] [[4000/3993|S10/S11]] so that ([[4/3]])/([[11/10]])<sup>3</sup> is tempered out results in an unusually high accuracy and efficient rank-2 temperament in the 2.3.11/5 subgroup for which interpretation as a rank-3 temperament in 2.3.5.11 (the no-7's [[11-limit]]) is natural, making [[10/9]] and [[12/11]] [[square superparticular|equidistant from 11/10]] and offering many fruitful tempering opportunities. Note therefore that [[porkypine]] can be seen as a trivial tuning of [[4000/3993|pine]] tempering out [[100/99]] = S10 and [[121/120]] = S11. | There are three notable [[harmonic entropy]] minima with this [[mos]] pattern. | ||
* The lowest accuracy one is [[porcupine]], in which two generators make a [[6/5]] and three make a [[4/3]]. The range of porcupine tunings is about 2\15 to 3\22. | |||
* Less well-known and more accurate is [[greeley]], in which two generators are still 6/5 but three fall quite short of a 4/3, but the scale happens to closely approximate a lot of higher-complexity intervals like [[10/7]], [[11/7]], etc. | |||
* Thirdly and finally, [[tempering out]] [[4000/3993|S10/S11]] so that ([[4/3]])/([[11/10]])<sup>3</sup> is tempered out results in an unusually high accuracy and efficient rank-2 temperament in the 2.3.11/5 subgroup for which interpretation as a rank-3 temperament in 2.3.5.11 (the no-7's [[11-limit]]) is natural, making [[10/9]] and [[12/11]] [[square superparticular|equidistant from 11/10]] and offering many fruitful tempering opportunities. Note therefore that [[porkypine]] can be seen as a trivial tuning of [[4000/3993|pine]] tempering out {{nowrap|[[100/99]] {{=}} S10}} and {{nowrap|[[121/120]] {{=}} S11}}. | |||
== Scale tree == | |||
{{MOS tuning spectrum | |||
| 5/2 = General range of porcupine | |||
| 2/1 = Optimum rank range for porcupine | |||
| 13/8 = Golden porcupine/hemikleismic | |||
| 10/7 = General range of greeley | |||
}} | |||
[[Category:8-tone scales]] | [[Category:8-tone scales]] | ||