Ploidacot/Omega-pentacot: Difference between revisions
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{{Breadcrumb}}{{Infobox ploidacot|Ploids=1|Shears=4|Cots=5|Pergen=[P8, P4/5]|Forms=12, 13, 25, 37|Title=Omega-pentacot|Wedgie=5}} | {{Breadcrumb}}{{Infobox ploidacot|Ploids=1|Shears=4|Cots=5|Pergen=[P8, P4/5]|Forms=12, 13, 25, 37|Title=Omega-pentacot (delta-pentacot)|Wedgie=5}} | ||
'''Omega-pentacot''' is a temperament archetype where the generator is a semitone, five of which stack to form a perfect fourth of [[4/3]], and the period is a [[2/1]] octave. Omega-pentacot temperaments usually generate the [[1L 11s]] and [[12L 1s]] MOS structures. Regular temperaments of omega-pentacot are [[Cluster MOS|cluster temperaments]] with 12 clusters of notes in an octave. | '''Omega-pentacot''' is a temperament archetype where the generator is a semitone, five of which stack to form a perfect fourth of [[4/3]], and the period is a [[2/1]] octave. Omega-pentacot temperaments usually generate the [[1L 11s]] and [[12L 1s]] MOS structures. Regular temperaments of omega-pentacot are [[Cluster MOS|cluster temperaments]] with 12 clusters of notes in an octave. | ||
== Intervals and notation == | == Intervals and notation == | ||
While there is no agreed-upon notation system for omega-pentacot, the following is based on interpreting the generator as a semitone (1/5 of a fourth), allowing for an ^ or v to stand for 1/5 of an ''inversed'' diminished second (the difference between diatonic semitone and chromatic semitone, equivalent to the [[Pythagorean comma]]), so vvvC# and ^^Db are enharmonic. | |||
{| class="wikitable" | {| class="wikitable" | ||
| Line 12: | Line 12: | ||
! Notation | ! Notation | ||
! Name | ! Name | ||
|- | |||
| −30 | |||
| 611.730 | |||
| F# | |||
| augmented fourth | |||
|- | |||
| −29 | |||
| 711.339 | |||
| ^^G | |||
| | |||
|- | |||
| −28 | |||
| 810.948 | |||
| vG# | |||
| | |||
|- | |||
| −27 | |||
| 910.557 | |||
| ^A | |||
| | |||
|- | |||
| −26 | |||
| 1010.166 | |||
| vvA# | |||
| | |||
|- | |||
| −25 | |||
| 1109.775 | |||
| B | |||
| major seventh | |||
|- | |||
| −24 | |||
| 9.384 | |||
| ^^C | |||
| | |||
|- | |||
| −23 | |||
| 108.993 | |||
| vC# | |||
| | |||
|- | |||
| −22 | |||
| 208.602 | |||
| ^D | |||
| | |||
|- | |||
| −21 | |||
| 308.211 | |||
| vvD# | |||
| | |||
|- | |||
| −20 | |||
| 407.820 | |||
| E | |||
| major third | |||
|- | |||
| −19 | |||
| 507.429 | |||
| ^^F | |||
| | |||
|- | |||
| −18 | |||
| 607.038 | |||
| vF# | |||
| | |||
|- | |||
| −17 | |||
| 706.647 | |||
| ^G | |||
| | |||
|- | |- | ||
| −16 | | −16 | ||
| 806.256 | | 806.256 | ||
| | | vvG# | ||
| | | | ||
|- | |- | ||
| Line 25: | Line 95: | ||
| −14 | | −14 | ||
| 1005.474 | | 1005.474 | ||
| | | ^^Bb | ||
| | | | ||
|- | |- | ||
| −13 | | −13 | ||
| 1105.083 | | 1105.083 | ||
| | | vB | ||
| | | | ||
|- | |- | ||
| −12 | | −12 | ||
| 4.692 | | 4.692 | ||
| | | ^C | ||
| | | | ||
|- | |- | ||
| −11 | | −11 | ||
| 104.301 | | 104.301 | ||
| | | vvC# | ||
| | | | ||
|- | |- | ||
| Line 50: | Line 120: | ||
| −9 | | −9 | ||
| 303.519 | | 303.519 | ||
| | | ^^Eb | ||
| | | | ||
|- | |- | ||
| −8 | | −8 | ||
| 403.128 | | 403.128 | ||
| | | vE | ||
| | | | ||
|- | |- | ||
| −7 | | −7 | ||
| 502.737 | | 502.737 | ||
| | | ^F | ||
| | | | ||
|- | |- | ||
| −6 | | −6 | ||
| 602.346 | | 602.346 | ||
| | | vvF# | ||
| | | | ||
|- | |- | ||
| Line 75: | Line 145: | ||
| −4 | | −4 | ||
| 801.564 | | 801.564 | ||
| | | ^^Ab | ||
| | | | ||
|- | |- | ||
| −3 | | −3 | ||
| 901.173 | | 901.173 | ||
| | | vA | ||
| | | | ||
|- | |- | ||
| −2 | | −2 | ||
| 1000.782 | | 1000.782 | ||
| | | ^Bb | ||
| | | | ||
|- | |- | ||
| −1 | | −1 | ||
| 1100.391 | | 1100.391 | ||
| | | vvB | ||
| | | | ||
|- | |- | ||
| Line 100: | Line 170: | ||
| 1 | | 1 | ||
| 99.609 | | 99.609 | ||
| | | ^^Db | ||
| | | | ||
|- | |- | ||
| 2 | | 2 | ||
| 199.218 | | 199.218 | ||
| | | vD | ||
| | | | ||
|- | |- | ||
| 3 | | 3 | ||
| 298.827 | | 298.827 | ||
| | | ^Eb | ||
| | | | ||
|- | |- | ||
| 4 | | 4 | ||
| 398.436 | | 398.436 | ||
| | | vvE | ||
| | | | ||
|- | |- | ||
| Line 125: | Line 195: | ||
| 6 | | 6 | ||
| 597.654 | | 597.654 | ||
| | | ^^Gb | ||
| | | | ||
|- | |- | ||
| 7 | | 7 | ||
| 697.263 | | 697.263 | ||
| | | vG | ||
| | | | ||
|- | |- | ||
| 8 | | 8 | ||
| 796.872 | | 796.872 | ||
| | | ^Ab | ||
| | | | ||
|- | |- | ||
| 9 | | 9 | ||
| 896.481 | | 896.481 | ||
| | | vvA | ||
| | | | ||
|- | |- | ||
| Line 150: | Line 220: | ||
| 11 | | 11 | ||
| 1095.699 | | 1095.699 | ||
| | | ^^Cb | ||
| | | | ||
|- | |- | ||
| 12 | | 12 | ||
| 1195.308 | | 1195.308 | ||
| | | vC | ||
| | | | ||
|- | |- | ||
| 13 | | 13 | ||
| 94.917 | | 94.917 | ||
| | | ^Db | ||
| | | | ||
|- | |- | ||
| 14 | | 14 | ||
| 194.526 | | 194.526 | ||
| | | vvD | ||
| | | | ||
|- | |- | ||
| Line 175: | Line 245: | ||
| 16 | | 16 | ||
| 393.744 | | 393.744 | ||
| ^^Fb | |||
| | |||
|- | |||
| 17 | |||
| 493.353 | |||
| vF | |||
| | |||
|- | |||
| 18 | |||
| 592.962 | |||
| ^Gb | |||
| | |||
|- | |||
| 19 | |||
| 692.571 | |||
| vvG | |||
| | |||
|- | |||
| 20 | |||
| 792.180 | |||
| Ab | |||
| minor sixth | |||
|- | |||
| 21 | |||
| 891.789 | |||
| ^^Bbb | |||
| | |||
|- | |||
| 22 | |||
| 991.398 | |||
| vBb | |||
| | |||
|- | |||
| 23 | |||
| 1091.007 | |||
| ^Cb | |||
| | |||
|- | |||
| 24 | |||
| 1190.616 | |||
| vvC | |||
| | |||
|- | |||
| 25 | |||
| 90.225 | |||
| Db | |||
| minor second | |||
|- | |||
| 26 | |||
| 189.834 | |||
| ^^Ebb | |||
| | |||
|- | |||
| 27 | |||
| 289.443 | |||
| vEb | |||
| | |||
|- | |||
| 28 | |||
| 389.052 | |||
| ^Fb | |||
| | | | ||
|- | |||
| 29 | |||
| 488.661 | |||
| vvF | |||
| | | | ||
|- | |||
| 30 | |||
| 588.270 | |||
| Gb | |||
| diminished fifth | |||
|} | |} | ||
A notable feature of omega-pentacot is the small comma, encountered after 12 steps, which represents one-fifth of a Pythagorean comma (or its equivalence, ''inversed'' diminished second). This makes omega-pentacot scales cluster around [[12edo]]. | |||
== Temperament interpretations == | == Temperament interpretations == | ||
| Line 184: | Line 326: | ||
Omega-pentacot temperaments are generally interpretated as quinticular temperaments; the generator is [[18/17]], five of them gives 4/3, so the [[quinticular comma]] (1419857/1417176) is tempered out. | Omega-pentacot temperaments are generally interpretated as quinticular temperaments; the generator is [[18/17]], five of them gives 4/3, so the [[quinticular comma]] (1419857/1417176) is tempered out. | ||
=== Quintilischis === | |||
{{See also| Schismatic family }} | |||
In quintilischis, the generator is 18/17, three of which make [[19/16]], five make 4/3, and 40 make [[10/1|10th harmonic]] in the 2.3.5.17.19 subgroup, so [[4624/4617]], [[6144/6137]], and [[6885/6859]] are tempered out. This temperament is a weak extension of [[schismic]], splitting the fourth in five. In the 2.3.5.7.17.19 subgroup, tempering out [[400/399]] (equating 20/19 and 21/20) leads to [[quintilipyth]] (12 & 253), and tempering out [[476/475]] (equating 19/17 with 28/25) leads to [[quintaschis]] (12 & 289). | |||
=== Quindromeda === | === Quindromeda === | ||
{{Main| Quindromeda family }} | {{Main| Quindromeda family }} | ||
In [[quindromeda]], the generator is 18/17, three | In [[quindromeda]], the generator is 18/17, three of which make 19/16, five make 4/3, and 28 make [[5/1|5th harmonic]] in the 2.3.5.17.19 subgroup, so [[1216/1215]], [[1445/1444]], and [[6144/6137]] are tempered out. Equating 225/224 with 256/255 leads to [[quintakwai]] (12 & 193), which tempers out 400/399 (also equating 20/19 and 21/20) in the 2.3.5.7.17.19 subgroup, and 361/360 with 400/399 leads to [[quintagar]] (12 & 217), which tempers out 476/475 (also equating 19/17 with 28/25) in the 2.3.5.7.17.19 subgroup. | ||
Equating 225/224 with 256/255 leads to [[quintakwai]] (12 & 193), which tempers out | |||
=== Quintaleap === | === Quintaleap === | ||
{{Main| Quintaleap family }} | {{Main| Quintaleap family }} | ||
In [[quintaleap]], the generator is 18/17, three | In [[quintaleap]], the generator is 18/17, three of which make 19/16, five make 4/3, and 16 make [[5/2]] in the 2.3.5.17.19 subgroup, so [[256/255]], [[361/360]], and [[4624/4617]] are tempered out. In the 2.3.5.7.17.19 subgroup, tempering out 400/399 leads to [[quintupole]] (12 & 121), and tempering out 476/475 leads to [[quinticosiennic]] (12 & 145). | ||
In the 2.3.5.7.17.19 subgroup, tempering out 400/399 | |||
=== Passion === | === Passion === | ||
{{Main| Passion family }} | {{Main| Passion family }} | ||
In [[passion]], the generator is [[16/15]], four | In [[passion]], the generator is [[16/15]], four of which make [[5/4]], and five make 4/3. It is best tuned with a slightly flat generator of about 98.7{{c}}, and follows that both 3 and 5 should be tuned sharp. The canonical mapping of 7 places [[7/4]] at 10 generators, and follows that the generator should be tuned flatter (about 98.1{{c}}). | ||
=== Ripple === | |||
{{Main| Ripple family }} | |||
In [[ripple]], the generator is [[27/25]], five of which make 4/3, and eight make [[8/5]]. It is best tuned with a sharp generator of about 101–102{{c}}, giving the [[11L 1s]] MOS structure (rather than 1L 11s), and follows that 3 should be tuned flat. | |||
[[Category:Ploidacots|Omega-pentacot]] | |||