Sim 24 note scale

In the liner notes for his CD "The Microtonal Music of Ezra Sims" he tells us he uses a 24 (out of 72) note scale. Does anyone know what the steps of this scale are, and what reasoning went into its adoption?

hi Gene,

> From: "Gene Ward Smith" <genewardsmith@juno.com>
> To: <tuning@yahoogroups.com>
> Sent: Friday, October 11, 2002 12:29 AM
> Subject: [tuning] Sim 24 note scale
>
>
> In the liner notes for his CD "The Microtonal Music of Ezra Sims"
> he tells us he uses a 24 (out of 72) note scale. Does anyone
> know what the steps of this scale are, and what reasoning went
> into its adoption?

here's the scale:

-------------------
Sims 24-note scale

72-EDO 72-EDO approximate
degree notation Semitones proportions

0 C 0 32
68 B> 11&1/3 31
65 B- 10&5/6 30
62 Bb> 10&1/3 29
58 Bb< 9&2/3 28
54 A 9 27
50 Ab> 8&1/3 26
46 Ab< 7&2/3 25
42 G 7 24
38 F#> 6&1/3 23
33 F#v 5&1/2 22
28 F< 4&2/3 21
23 E- 3&5/6 20 30 40
20 Eb> 3&1/3 39
20 Eb> 3&1/3 29
18 Eb 3 19 38
16 Eb< 2&2/3 28
15 Ebv 2&1/2 37
12 D 2 18 27 36
9 Dv 1&1/2 35
8 Db> 1&1/3 26
6 Db 1 17 34
4 Db< 2/3 25
3 Dbv 1/2 33
0 C 0 16 24 32

(Sims sometimes uses 2^(69/72) B^ to represent 31/16.)

[use "Expand Messages" to view this correctly on the
Yahoo website]

The usual scale is the one with proportions 24:25:26:27:28:29:30
("1/3-tones") at the bottom. Sometimes Sims feels the need
to have 1/4-tones instead, and uses the notes with proportions
32:33:34:35:36:37:38:39:40. The two sets are not used together.

---------

this was quoted from a post i sent a few years ago:
/tuning/topicId_22968.html#23086?expand=1

in which i also explain of Sims's derivation of the scale
in detail.

i also notice that there are actually only 23 different pitches,
because Sims is using 2^(20/72) to represent both the ratios
29:24 and 39:32.

the latter is basically midway between 20 and 21 degrees of
72edo (at ~20.54895976 degrees), but is actually better
represented by 2^(21/72).

there is also a fair amount of ambiguity in representing 29:24
by 2^(20/72), as it is ~19&2/3 degrees of 72edo.

-monz
"all roads lead to n^0"

--- In tuning@y..., "monz" <monz@a...> wrote:

/tuning/topicId_39476.html#39478

> ---------
>
> this was quoted from a post i sent a few years ago:
> /tuning/topicId_22968.html#23086?expand=1
>
> in which i also explain of Sims's derivation of the scale
> in detail.
>

***Thanks so much, Monz, for refreshing my memory of this post which
was, actually, only in May 2001. However, it was before I was using
the 72-tET system *myself* so times do change... :)

Joe