A meantone tuning with six 7-limit tetrads

Hi, I'm new to this list. Greetings from Brisbane, Australia.

Has anyone seen the following tuning before?

It's a choice of 12 from 31-TET which has many 7-limit harmonies. It has the advantage of mapping to an ordinary keyboard, approximating equal tempered, embedding some ordinary diatonic scales within it (C, G, Em-harm) and having its note names conform to the familiar western system, since it is syntonic (4 fifths = 1 third).

C Db D D# E F F# G Ab A A# B C
3 2 2 3 3 2 3 3 2 2 3 3 (number of 31-TET steps between notes)

As a sequence of 5ths it is:
Db Ab - - F C G D A E B F# - - D# A#

It gives the following 7-limit tetrads
Augmented sixths (7:6:5:4)
F A C D#
C E G A#
Db F Ab B

Minor diminished sevenths (1/4:1/5:1/6:1/7)
B D F# Ab
E G B Db
D# F# A# C

All but one of its 12 notes (either Db or A#) can be covered by three of these tetrads. All can be covered by four.

Major sevenths are also available on F and C while dominant sevenths are available on G and D and of course minors on some other degrees.

There are 3 wolf fifths (A#Db, AbD#, F#Db) however they may be considered as 11-limit intervals with an accuracy of 10 cents, if you believe in such things.

I think most of (if not all of) what would otherwise have been wolf thirds have become 7-limit intervals with an error of at most 4.1 cents.

In case you want to dial it up on a synthesizer and give it a try, here are the optimum offsets from 12-TET given one cent resolution.

C Db D D# E F F# G Ab A A# B
10 26 4 -19 -3 13 -9 7 23 0 -22 -6

This gives errors relative to the just intervals of only:
fifth 3:2 -5.0 cents (-6.0 for D A)
third 5:4 0.7 cents
minor third 6:5 -5.6 cents (-6.6 for D F and F# A)
augmented sixth 7:4 -0.8 cents
augmented fourth 7:5 -1.5 cents
augmented second 7:6 4.1 cents

I developed it after reading Paul Erlich's criteria for 7-limit generalised-diatonic scales (in which he finds that only a 10 of 22-TET is suitable) and seeing a 7-limit just tuning given in the manual for Bill Cooper's excellent RealTime Tuner as:
"1, 15/4, 9/8, 7/6, 5/4, 4/3, 7/5, 3/2, 14/9, 5/3, 7/4, 15/8"
where 15/4 was no doubt intended to be 15/14. Of course the above 12 of 31-TET (or meantone-type) scale has more 7-limit tetrads and fewer wolves than this just scale.

Regards,
-- Dave Keenan
http://dkeenan.com