Here's a 12-note scale which is comparable to the ones I just did by

tempering Carl's. I took all the JI scales built from (15/14)^3 (16/15)^4

(21/20)^3 (25/24)^2 which consisted of two indentical tetrachords

separated by a 9/8=15/14 21/20. I got two scales and their inversions,

isomorphic by the 21/20 <==> 25/24 transformation. These scales turned

out to be adapted to the {225/224, 385/384} temperament, and on tempering

I ended up with just one scale (modulo modes) and its inversion. I took

this down a fourth to get some dominant harmony, and ended up with this:

1-21/20-9/8-6/5-5/4-21/16-7/5-3/2-8/5-5/3-7/4-28/15

27 (7-limit) intervals, 20 triads

Tempering it, I got the following:

! tetra.scl

! [61, 83, 83, 47, 61, 83, 83, 83, 47, 61, 83, 83]

{225/224, 385/384} tempering of two-tetrachord 12-note scale

! 858-et version of 1-21/20-9/8-6/5-5/4-21/16-7/5-3/2-8/5-5/3-7/4-28/15

12

!

85.31468531

201.3986014

317.4825175

383.2167832

468.5314685

584.6153846

700.6993007

816.7832168

882.5174825

967.8321678

1083.916084

2/1

46 (11 limit) intervals 74 triads

Something for Carl to think about.