Misty: Difference between revisions

From XenReference
Line 26: Line 26:
!JI
!JI
|-
|-
| -1
! -1
|1103.1
|1103.1
|189/100
|189/100
Line 34: Line 34:
|'''3/2'''
|'''3/2'''
|-
|-
|class="thl"|0
! class="thl" |0
|class="thl"|'''0'''
| class="thl" |'''0'''
|class="thl"|'''1/1'''
|class="thl"|'''1/1'''
|class="thl"|400
|class="thl"|400
Line 42: Line 42:
|class="thl"|100/63
|class="thl"|100/63
|-
|-
|1
!1
|96.9
|96.9
|135/128, 200/189
|135/128, 200/189
Line 50: Line 50:
|42/25
|42/25
|-
|-
|2
!2
|193.8
|193.8
|28/25
|28/25
Line 58: Line 58:
|16/9
|16/9
|-
|-
|3
!3
|290.6
|290.6
|32/27
|32/27
Line 66: Line 66:
|15/8
|15/8
|-
|-
|4
!4
|'''387.5'''
|'''387.5'''
|'''5/4'''
|'''5/4'''
Line 74: Line 74:
|125/126, 224/225
|125/126, 224/225
|-
|-
|5
!5
|484.4
|484.4
|
|
Line 82: Line 82:
|21/20
|21/20
|-
|-
|6
!6
|581.3
|581.3
|7/5
|7/5
Line 90: Line 90:
|10/9
|10/9
|-
|-
|7
!7
|678.2
|678.2
|40/27
|40/27
Line 98: Line 98:
|75/64
|75/64
|-
|-
|8
!8
|775.1
|775.1
|25/16
|25/16
Line 106: Line 106:
|56/45
|56/45
|-
|-
|9
!9
|871.9
|871.9
|
|
Line 114: Line 114:
|21/16
|21/16
|-
|-
|10
!10
|'''968.8'''
|'''968.8'''
|'''7/4'''
|'''7/4'''

Revision as of 02:20, 3 April 2026

Misty, 12 & 87, is a 7-limit temperament with

  • generator 3/2 (period-reduced: 25/21)
  • period 1/3-octave which represents 63/50, the difference between 56/25 and 16/9.

In Misty, the diesis 128/125 is split into three 126/125s (which also represent 225/224). As a result, the octave is also split into three, because by definition a 5/4 and a third of 128/125 reach 1\3. The generator is 135/128, which stacks four times to 5/4 and raises by a 400c period to 4/3. Because it is a weak extension of Didacus, 5/4 is split into two parts that stack 5 times to 7/4.

Misty results from tempering out the following 2 commas:

  • 5120/5103, the aberschisma, which equates 64/63 and 81/80
  • 3136/3125, the Didacus comma

Theory

Intervals

Misty has the structural property of dividing the comma 81/80~64/63 into two equal kleismas 126/125~225/224.

# periods +0 (mod 3) +1 (mod 3) +2 (mod 3)
# gens Cents* JI Cents* JI Cents* JI
-1 1103.1 189/100 303.1 25/21 703.1 3/2
0 0 1/1 400 63/50 800 100/63
1 96.9 135/128, 200/189 496.9 4/3 896.9 42/25
2 193.8 28/25 593.8 45/32 993.8 16/9
3 290.6 32/27 690.6 1090.6 15/8
4 387.5 5/4 787.5 63/40, 128/81 1187.5 125/126, 224/225
5 484.4 884.4 5/3 84.4 21/20
6 581.3 7/5 981.3 181.3 10/9
7 678.2 40/27 1078.2 28/15 278.2 75/64
8 775.1 25/16 1175.1 63/64, 80/81 375.1 56/45
9 871.9 71.9 25/24 471.9 21/16
10 968.8 7/4 168.8 568.8 50/36

(* exact-2/1, exact-7/4 tuning; octave-reduced)

Derivation of 1/3-octave period

  1. 128/125 = 126/125 * 64/63 is equated to 126/125 * 81/80 by the aberschisma
  2. 81/80 itself = 126/125 * 225/224
  3. Didacus equates 225/224 to 126/125
  4. So we have 128/125 ~= 126/125 * 81/80 = 126/125 * 126/125 * 225/224 ~= (126/125)3
  5. Hence, 2/1 = 5/4 * 5/4 * 5/4 * 128/125 ~= (5/4 * 126/125)3 = (63/50)3