OTC 7L 7s

Omnitetrachordal MOS scale

7L+7s

14 tones (6+2+6)

temperament: whitewood

This scale has some unusual properties:

• it has only two modes
• either mode may be split in any of the three possible omnitetrachordal ways (9/8-4/3-4/3, 4/3-9/8-4/3, 4/3-4/3-9/8)
• it is its own dual (changing all L to s, and vice versa, gives the same scale)
• the (imperfect) tunings of 9/8 and 4/3 are independent of L/s ratio

See also OTC 5L+5s (blackwood) and OTC 12L+12s (catler/compton).

P = undefined (-1?)

Q = 4.2777408456 (4/3 = 3L+2.5s)

L = 85.71 to 171.43 cents (138.95 cents @ Q)

s = 0.00 to 85.71 cents (32.48 cents @ Q)

9/8 = L+s (171.43 cents for any L/s)

4/3 = 3L+3s (514.29 cents for any L/s)

generator = s (0.00 to 85.71 cents)

period = 1/7 octave (171.43 cents)

notable EDOs: 21, 28, 35 (for 35edo, use L/s=3/2)

all modes:

Ls LsLsLs LsLsLs	LsLsLs Ls LsLsLs	LsLsLs LsLsLs Ls
sL sLsLsL sLsLsL	sLsLsL sL sLsLsL	sLsLsL sLsLsL sL

See also

• Omnitetrachordality
• Gallery of omnitetrachordal scales