memo

12ET-complementary comma pairs (e.g. syntonic-schismatic relation)

M3 or d4 A: 4*P5=M3+2*P8 B: 8*P5+d4=5*P8 Remarks
32/27 2187/2048=[-11 7 256/243=[8 -5 A/B=[-19 12, A: (7edo), B: (5edo)
6/5 135/128=[-7 3 1 (64/63)^2*(245/243)=[12 -9 1 A/B=[-19 12, A: Mavila, B: Superpyth
11/9 729/704=[-6 6 0 0 -1 (64/63)^2/(99/98)=[13 -6 0 0 -1 A/B=[-19 12, A: Meanenneadecal?, B: Supra
8192/6561 531441/524288=[-19 12 1/1 A: (12edo)
5/4 81/80=[-4 4 -1 32805/32768=[-15 8 1 A*B=[-19 12, A: Meantone, B: Schismatic
81/64 1/1 531441/524288=[-19 12 B: (12edo)
9/7 64/63=[6 -2 0 -1 59049/57344=[-13 10 0 -1 B/A=[-19 12, A: Archytas clan, B: Septimal meantone
4/3 256/243=[8 -5 2187/2048=[-11 7 B/A=[-19 12, A: (5edo), B: (7edo)

Q: Mavila must have the fifth flatter than 7edo's, why be placed between 7edo and 5edo?

A: I wrote the 32/27 in this table as a monzo-ish value. 32/27 constructed of P5 & P8 will much sharper when flatter P5 situation.

(3/2)^(1/2) 2187/2048=[-11 7 17-comma=[27 -17 A/B=[-38 24, A: (7edo), B: (17edo)
(3/2)^(4/7) 531441/524288=[-19 12 531441/524288=[-19 12 A*B=[-38 24, A: (12edo), B: (12edo)
(3/2)^(2/3) 256/243=[8 -5 [-41 26 B/A=[-49 31, A: (5edo), B: (26edo)

temperaments with septimal tritones

Fifthspan -8 -6 4 6 Remarks
Septimal meantone 32/25 10/7 5/4 7/5 Good 4:5:7 in 10 fifthspanp-p
Dominant 32/25 7/5 5/4 10/7 inaccurate
Schism 5/4 10/7 80/63 7/5 inaccurate
Garibaldi 5/4 7/5 80/63 10/7 Good 4:5:6:7 in 15 fifthspanp-p
Good 4:6 & 5:7 in 6 fifthspanp-p
Hemififths 7/5 10/7 5/4 is at 12.5 fifthspan