Ploidacot/Gamma-pentacot

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Gamma-pentacot is a temperament archetype where the generator is a subneutral third, five of which make a perfect eleventh of 8/3, and the period is a 2/1 octave. Gamma-pentacot temperaments typically generate the 4L 3s and 7L 4s MOS scales, and they split the chromatic semitone into five equal parts, creating "supraminor", "subneutral", "supraneutral", and "submajor" intervals.

Gamma-pentacot
Pergen [P8, P11/5]
Numeral form 3-sheared 5-cot
Pure generator size 339.61 ¢
Pure period size 1200 ¢
Forms 7, 11, 18, 25
Characteristic multival entry 5

Gamma-pentacot temperaments often generate 7L 11s, 7L 18s, 7L 25s, 7L 32s, and 7L 39s as chromatic scales, and for particularly sharp tunings 39L 7s.

Intervals and notation

While there is no agreed-upon notation system for gamma-pentacot, the notation provided here is based on interpreting the generator as a subneutral third, and allowing for an ^ or v to stand for 1/5 of a chromatic semitone, so ^^^C and vvC# are enharmonic.

Gamma-pentacot intervals (assuming pure fifth and octave)
# Cents Notation Name
−30 611.730 F# augmented fourth
−29 951.339 ^^A
−28 90.948 vC#
−27 430.557 ^E
−26 770.166 vvG#
−25 1109.775 B major seventh
−24 249.384 ^^D
−23 588.993 vF#
−22 928.602 ^A
−21 68.211 vvC#
−20 407.820 E major third
−19 747.429 ^^G
−18 1087.038 vB
−17 226.647 ^D
−16 566.256 vvF#
−15 905.865 A major sixth
−14 45.474 ^^C
−13 385.083 vE
−12 724.692 ^G
−11 1064.301 vvB
−10 203.910 D major second
−9 543.519 ^^F
−8 883.128 vA
−7 22.737 ^C
−6 362.346 vvE
−5 701.955 G perfect fifth
−4 1041.564 ^^Bb
−3 181.173 vD
−2 520.782 ^F
−1 860.391 vvA
0 0.000 C perfect unison
1 339.609 ^^Eb
2 679.218 vG
3 1018.827 ^Bb
4 158.436 vvD
5 498.045 F perfect fourth
6 837.654 ^^Ab
7 1177.263 vC
8 316.872 ^Eb
9 656.481 vvG
10 996.090 Bb minor seventh
11 135.699 ^^Db
12 475.308 vF
13 814.917 ^Ab
14 1174.526 vvC
15 294.135 Eb minor third
16 633.744 ^^Gb
17 973.353 vBb
18 112.962 ^Db
19 452.571 vvF
20 792.180 Ab minor sixth
21 1131.789 ^^Cb
22 271.398 vEb
23 611.007 ^Gb
24 950.616 vvBb
25 90.225 Db minor second
26 429.834 ^^Fb
27 769.443 vAb
28 1109.052 ^Cb
29 248.661 vvEb
30 588.270 Gb diminished fifth

Temperament interpretations

An obvious interpretation for gamma-pentacot is amity, 5/4 is equated to 4 octaves minus 13 generators, and 7/4 is equated to 17 generators minus 4 octaves. Other interpretations include sixix, which interprets 6/5 as a generator.