Ploidacot/Triploid dicot

Triploid dicot is a temperament archetype with a 1/3-octave period, and a generator of a neutral third. In a pure tuning, the generator is exactly a half of 3/2. But the alternative generator, a quartertone, with size around 49¢ is rather easier to grasp.

Triploid dicot
Pergen [P8/3, P5/2]
Numeral form 3-ploid 2-cot
Pure generator size 49.02 ¢
Pure period size 400 ¢
Forms 18, 21, 24
Characteristic multival entry 6

Triploid dicot temperaments usually generate the 3L 12s, 3L 15s, and 3L 18s MOS structures.

Intervals and notation

While there is no agreed-upon notation system for triploid dicot, the following is based on interpreting the generator as a quartertone (1/6 of a minor third), allowing for an ^ or v to stand for 1/3 of an inversed diminished second (the difference between diatonic semitone and chromatic semitone, equivalent to the Pythagorean comma), along with neutral chain-of-fifths notation, so vvC# and ^Db are enharmonic.

Triploid dicot intervals (assuming pure fifth and octave)
# Ploid 1 Ploid 2 Ploid 3
Cents Notation Name Cents Notation Name Cents Notation Name
−12 211.73 ^D 611.73 F# augmented fourth 1011.73 vA#
−11 260.75 Dt semiaugmented second 660.75 vFt# 1060.75 ^Bd
−10 309.78 vD# 709.78 ^G 1109.78 B major seventh
−9 358.80 ^Ed 758.80 Gt semiaugmented fifth 1158.80 vBt
−8 7.82 ^C 407.82 E major third 807.82 vG#
−7 56.84 Ct semiaugmented unison 456.84 vEt 856.84 ^Ad
−6 105.87 vC# 505.87 ^F 905.87 A major sixth
−5 154.89 ^Dd 554.89 Ft semiaugmented fourth 954.89 vAt
−4 203.91 D major second 603.91 vF# 1003.91 ^Bb
−3 252.93 vDt 652.93 ^Gd 1052.93 Bd neutral seventh
−2 301.96 ^Eb 701.96 G perfect fifth 1101.96 vB
−1 350.98 Ed neutral third 750.98 vGt 1150.98 ^Cd
0 0 C unison 400 vE 800 ^Ab
1 49.02 vCt 449.02 ^Fd 849.02 Ad neutral sixth
2 98.04 ^Db 498.04 F perfect fourth 898.04 vA
3 147.07 Dd neutral second 547.07 vFt 947.07 ^Bdb
4 196.09 vD 596.09 ^Gb 996.09 Bb minor seventh
5 245.11 ^Edb 645.11 Gd semidiminished fifth 1045.11 vBd
6 294.13 Eb minor third 694.13 vG 1094.13 ^Cb
7 343.16 vEd 743.16 ^Adb 1143.16 Cd semidiminished octave
8 392.18 ^Fb 792.18 Ab minor sixth 1192.18 vC
9 41.20 ^Ddb 441.20 Fd semidiminished fourth 841.20 vAd
10 90.22 Db minor second 490.22 vF 890.22 ^Bbb
11 139.25 vDd 539.25 ^Gdb 939.25 Bdb semidiminished seventh
12 188.27 ^Ebb 588.27 Gb diminished fifth 988.27 vBb

Temperament interpretations

An obvious interpretation for triploid dicot is hemiaug, a weak extension of augmented. The period is 5/4~14/11 and the generator is 36/35~40/39~45/44, so that 3/2 is two periods down two generators, 7/4 at one octave down five generators, 11/8 at two periods down five generators, and 13/8 at two periods up one generator.