Peppermint-24

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=Peppermint 24= 

[[http://launch.groups.yahoo.com/group/tuning/message/40057|Original article]] by Margo Schulter, on the Yahoo tuning forum.

[[code]]
 An interesting feature of tuning systems, as implemented on keyboards
 (conventional or alternative), is the [[keyboard mappings|mapping]] of pure or tempered
 ratios to positions on the keyboard layout.

 Here I shall explore the mapping of approximate ratios, and especially
 of superparticular and other ratios within [[Harry Partch]]'s larger
 17-limit set, in the tuning system and keyboard arrangement I call
 Peppermint 24.

 Peppermint 24 takes as its basis a [[Regular Temperaments|regular temperament]] mentioned in
 [[Erv Wilson|Ervin Wilson]]'s Scale Tree and described on the Tuning List by [[Keenan Pepper]],
 with a fifth of about 704.096 cents, and a precise ratio of
 [[Phi]], the Golden Section (~1.618) between the larger chromatic semitone
 (e.g. C-C#) at about 128.669 cents and the smaller diatonic semitone
 (e.g. C#-D) at about 79.522 cents.

 In Peppermint 24, two regular 12-note chains of this temperament are
 placed at a distance of approximately 58.680 cents, so as to yield
 some pure ratios of 6:7 (~266.871 cents).

 Here is a 24-note keyboard arrangement, with an asterisk (*) showing a
 note on the upper keyboard:

     187.349  346.393              683.253    891.445 1050.488
       C#*      Eb*                   F#*       G#*     Bb*
  C*        D*          E*      F*        G*        A*       B*     C*
58.680   266.871    475.062  554.584   762.775  970.967  1179.158 1258.680
           7/6
-------------------------------------------------------------------------
     128.669  287.713              624.574    832.765 991.809
        C#      Eb                    F#         G#     Bb
  C         D           E       F          G         A        B     C
  0       208.191    416.382 495.904    704.096   912.287 1120.478 1200


 In the following catalogue of some ratio equivalents and mappings, I
 will focus on intervals no further from just than 8:9 or 9:16, which
 vary from their pure sizes by about 4.282 cents (twice the tempering
 of the fifth, at about 2.141 cents wide of 2:3).

 Octave numbers appear in a MIDI-style notation, with C4 as middle C;
 just ratios and tempered equivalents are given values in cents, shown
 in parentheses, with tempered variations in cents also shown.

 To describe the 58.68-cent interval between the two keyboards, whose
 addition or subtraction plays a role in obtaining or approximating
 many ratios, I shall the term "quasi-diesis," or QD for short. This
 "artificial" diesis-like interval is actually somewhat larger than the
 natural diesis in the regular Wilson/Pepper temperament at about 49.15
 cents (12 tempered fifths less 7 pure octaves).

 As this partial catalogue might suggest, many ratios of 2-3-7-9-11-13
 are represented quite accurately, with 14:17:21 and related ratios
 also closely approximated.


----
 1. Multiplex (n:1) and [[superparticular]] (n+1:n) intervals
----

 1:2 (1200) -- This is the usual octave (e.g. F3-F4), at a pure 1:2.

 2:3 (701.96) -- This is the usual fifth (e.g. F3-C4, 704.10, +2.14).

 3:4 (498.04) -- Usual fourth (e.g. C4-F4, 495.90, -2.14).

 6:7 (266.87) -- Major second + QD (e.g. D4-E*4), at a pure 6:7.

 7:8 (231.17) -- Minor third - QD (e.g. C*4-Eb4, 229.03, -2.14)

 8:9 (203.91) -- Usual major second (e.g. C4-D4, 208.19, +4.28)

 11:12 (150.64) -- Major second - QD (e.g. C*4-D4, 149.51, -1.13)

 12:13 (138.57) -- Minor second + QD (e.g. E4-F*4, 138.20, -0.37)

 13:14 (128.30) -- Usual apotome (e.g. C4-C#4, 128.67, +0.37)

 17:18 (98.95) -- Diminished third - QD (e.g. G#*4-Bb4, 100.36, -1.41)

 21:22 (80.54) -- Usual minor second (e.g. E4-F4, 79.52, -1.02)

 24:25 (70.67) -- Apotome - QD (e.g. E*4-Eb4, 69.99, -0.68)

 27:28 (62.96) -- QD (e.g. E4-E*4, 58.68, -4.28)


----
 2. Other ratios -- many within 17-odd limit
----

 4:7 (968.83) -- Major sixth + QD (e.g. G3-E*4, 970.97, +2.14)

 7:9 (435.08) -- Fourth - QD (e.g. G*4-C5, 437.22, +2.14)

 7:12 (933.13) -- Minor seventh - QD (e.g. G*3-F4), at a pure 7:12.

 9:14 (764.92) -- Fifth + QD (e.g. G4-D*5, 762.78, -2.14)

 9:16 (996.09) -- Usual minor seventh (e.g. G4-F4, 991.81, -4.28)

 6:11 (1049.36) -- Minor seventh + QD (e.g. G3-F*4, 1050.49, +1.13)

 7:11 (782.49) -- Usual minor sixth (e.g. A3-F4, 783.62, +1.13)

 8:11 (551.32) -- Fourth + QD (e.g. G3-C*4, 554.58, +3.27)

 9:11 (347.41) -- Minor third + QD (e.g. G3-Bb*3, 346.39, -1.02)

 8:13 (840.53) -- Minor sixth + QD (e.g. G3-Eb*3, 842.30, +1.77)

 9:13 (636.62) -- Diminished fifth + QD (e.g. A3-Eb*4, 634.11, -2.51)

 11:13 (289.21) -- Usual minor third (e.g. D3-F3, 287.71, -1.50)

 11:14 (417.51) -- Usual major third (e.g. D3-F#3, 416.38, -1.13)

 11:16 (648.68) -- Fifth - QD (e.g. F*3-C4, 645.42, -3.27)

 11:18 (852.59) -- Major sixth - QD (e.g. G*4-E5, 853.61, +1.02)

 11:21 (1119.46) -- Usual major seventh (e.g. F3-E4, 1120.48, +1.02)

 12:17 (603.00) -- Augmented third + QD (e.g. Eb4-G#*4, 603.73, +0.73)

 13:16 (359.47) -- Major third - QD (e.g. C*4-E4, 357.70, -1.77)

 13:18 (563.38) -- Augmented fourth - QD (e.g. C*4-F#4, 565.89, +2.51)

 13:21 (830.25) -- Usual augmented fifth (e.g. C4-G#4, 832.76, +2.51)

 13:22 (910.79) -- Usual major sixth (e.g. G3-E4, 912.29, +1.50)

 13:23 (987.75) -- Usual minor seventh (e.g. D4-C5, 991.81, +4.06)

 13:24 (1061.43) -- Major seventh - QD (e.g. F*3-E4), 1061.80, +0.37)

 14:17 (336.13) -- Usual augmented second (e.g. F4-G#4, 336.86, +0.73)

 14:27 (1137.04) -- Octave - QD (e.g. F*4-F5, 1141.32, +4.28)

 15:17 (216.69) -- Diminished third + QD (e.g. C#4-Eb*4, 217.72, +1.04)

 16:21 (470.71) -- Major third + QD (e.g. C4-E*4, 475.06, +4.28)

 16:23 (628.27) -- Usual augmented fourth (e.g. C4-F#4, 624.57, -3.70)

 18:23 (424.36) -- Diminished fourth + QD (e.g. B4-Eb*5, 425.91, +1.55)

 16:25 (772.63) -- Diminished fourth + QD (e.g. F#4-Bb*4, 774.09, +1.46)

 17:20 (281.36) -- Augmented second - QD (e.g. F*4-G#4, 278.18, -3.18)

 17:21 (365.83) -- Usual diminished fourth (e.g. F#4-Bb4, 367.24, +1.41)

 17:28 (863.87) -- Usual diminished seventh (e.g. F#4-Eb4, 863.14, -0.73)

 21:34 (834.17) -- Usual augmented fifth (e.g. F3-C#4, 832.76, +1.41)

 28:51 (1038.08) -- Usual augmented sixth (e.g. Eb3-C#4, 1040.96, +2.87)

 21:23 (157.49) -- Usual diminished third (e.g. C#4-Eb4, 159.04, +1.55)

 21:26 (369.75) -- Usual diminished fourth (e.g. C#4-F4, 367.24, -1.51)

 23:27 (277.59) -- Augmented second - QD (e.g. Eb*4-F#4, 278.18, +0.59)

 26:33 (412.75) -- Usual major third (e.g. F4-A4, 416.38, +3.63)

 28:33 (284.45) -- Usual minor third (e.g. E4-G4, 287.71, +3.27)

 33:56 (915.55) -- Usual major sixth (e.g. G4-E5, 912.29, -3.27)

[[code]]

Original HTML content:

<html><head><title>Peppermint-24</title></head><body><!-- ws:start:WikiTextHeadingRule:1:&lt;h1&gt; --><h1 id="toc0"><a name="Peppermint 24"></a><!-- ws:end:WikiTextHeadingRule:1 -->Peppermint 24</h1>
 <br />
<a class="wiki_link_ext" href="http://launch.groups.yahoo.com/group/tuning/message/40057" rel="nofollow">Original article</a> by Margo Schulter, on the Yahoo tuning forum.<br />
<br />
<!-- ws:start:WikiTextCodeRule:0:
&lt;pre class=&quot;text&quot;&gt; An interesting feature of tuning systems, as implemented on keyboards&lt;br/&gt; (conventional or alternative), is the [[keyboard mappings|mapping]] of pure or tempered&lt;br/&gt; ratios to positions on the keyboard layout.&lt;br/&gt;&lt;br/&gt; Here I shall explore the mapping of approximate ratios, and especially&lt;br/&gt; of superparticular and other ratios within [[Harry Partch]]'s larger&lt;br/&gt; 17-limit set, in the tuning system and keyboard arrangement I call&lt;br/&gt; Peppermint 24.&lt;br/&gt;&lt;br/&gt; Peppermint 24 takes as its basis a [[Regular Temperaments|regular temperament]] mentioned in&lt;br/&gt; [[Erv Wilson|Ervin Wilson]]'s Scale Tree and described on the Tuning List by [[Keenan Pepper]],&lt;br/&gt; with a fifth of about 704.096 cents, and a precise ratio of&lt;br/&gt; [[Phi]], the Golden Section (~1.618) between the larger chromatic semitone&lt;br/&gt; (e.g. C-C#) at about 128.669 cents and the smaller diatonic semitone&lt;br/&gt; (e.g. C#-D) at about 79.522 cents.&lt;br/&gt;&lt;br/&gt; In Peppermint 24, two regular 12-note chains of this temperament are&lt;br/&gt; placed at a distance of approximately 58.680 cents, so as to yield&lt;br/&gt; some pure ratios of 6:7 (~266.871 cents).&lt;br/&gt;&lt;br/&gt; Here is a 24-note keyboard arrangement, with an asterisk (*) showing a&lt;br/&gt; note on the upper keyboard:&lt;br/&gt;&lt;br/&gt;     187.349  346.393              683.253    891.445 1050.488&lt;br/&gt;       C#*      Eb*                   F#*       G#*     Bb*&lt;br/&gt;  C*        D*          E*      F*        G*        A*       B*     C*&lt;br/&gt;58.680   266.871    475.062  554.584   762.775  970.967  1179.158 1258.680&lt;br/&gt;           7/6&lt;br/&gt;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;&amp;#45;-&lt;br/&gt;     128.669  287.713              624.574    832.765 991.809&lt;br/&gt;        C#      Eb                    F#         G#     Bb&lt;br/&gt;  C         D           E       F          G         A        B     C&lt;br/&gt;  0       208.191    416.382 495.904    704.096   912.287 1120.478 1200&lt;br/&gt;&lt;br/&gt;&lt;br/&gt; In the following catalogue of some ratio equivalents and mappings, I&lt;br/&gt; will focus on intervals no further from just than 8:9 or 9:16, which&lt;br/&gt; vary from their pure sizes by about 4.282 cents (twice the tempering&lt;br/&gt; of the fifth, at about 2.141 cents wide of 2:3).&lt;br/&gt;&lt;br/&gt; Octave numbers appear in a MIDI-style notation, with C4 as middle C;&lt;br/&gt; just ratios and tempered equivalents are given values in cents, shown&lt;br/&gt; in parentheses, with tempered variations in cents also shown.&lt;br/&gt;&lt;br/&gt; To describe the 58.68-cent interval between the two keyboards, whose&lt;br/&gt; addition or subtraction plays a role in obtaining or approximating&lt;br/&gt; many ratios, I shall the term &amp;quot;quasi-diesis,&amp;quot; or QD for short. This&lt;br/&gt; &amp;quot;artificial&amp;quot; diesis-like interval is actually somewhat larger than the&lt;br/&gt; natural diesis in the regular Wilson/Pepper temperament at about 49.15&lt;br/&gt; cents (12 tempered fifths less 7 pure octaves).&lt;br/&gt;&lt;br/&gt; As this partial catalogue might suggest, many ratios of 2-3-7-9-11-13&lt;br/&gt; are represented quite accurately, with 14:17:21 and related ratios&lt;br/&gt; also closely approximated.&lt;br/&gt;&lt;br/&gt;&lt;br/&gt;&amp;#45;&amp;#45;&amp;#45;-&lt;br/&gt; 1. Multiplex (n:1) and [[superparticular]] (n+1:n) intervals&lt;br/&gt;&amp;#45;&amp;#45;&amp;#45;-&lt;br/&gt;&lt;br/&gt; 1:2 (1200) &amp;#45;- This is the usual octave (e.g. F3-F4), at a pure 1:2.&lt;br/&gt;&lt;br/&gt; 2:3 (701.96) &amp;#45;- This is the usual fifth (e.g. F3-C4, 704.10, +2.14).&lt;br/&gt;&lt;br/&gt; 3:4 (498.04) &amp;#45;- Usual fourth (e.g. C4-F4, 495.90, -2.14).&lt;br/&gt;&lt;br/&gt; 6:7 (266.87) &amp;#45;- Major second + QD (e.g. D4-E*4), at a pure 6:7.&lt;br/&gt;&lt;br/&gt; 7:8 (231.17) &amp;#45;- Minor third - QD (e.g. C*4-Eb4, 229.03, -2.14)&lt;br/&gt;&lt;br/&gt; 8:9 (203.91) &amp;#45;- Usual major second (e.g. C4-D4, 208.19, +4.28)&lt;br/&gt;&lt;br/&gt; 11:12 (150.64) &amp;#45;- Major second - QD (e.g. C*4-D4, 149.51, -1.13)&lt;br/&gt;&lt;br/&gt; 12:13 (138.57) &amp;#45;- Minor second + QD (e.g. E4-F*4, 138.20, -0.37)&lt;br/&gt;&lt;br/&gt; 13:14 (128.30) &amp;#45;- Usual apotome (e.g. C4-C#4, 128.67, +0.37)&lt;br/&gt;&lt;br/&gt; 17:18 (98.95) &amp;#45;- Diminished third - QD (e.g. G#*4-Bb4, 100.36, -1.41)&lt;br/&gt;&lt;br/&gt; 21:22 (80.54) &amp;#45;- Usual minor second (e.g. E4-F4, 79.52, -1.02)&lt;br/&gt;&lt;br/&gt; 24:25 (70.67) &amp;#45;- Apotome - QD (e.g. E*4-Eb4, 69.99, -0.68)&lt;br/&gt;&lt;br/&gt; 27:28 (62.96) &amp;#45;- QD (e.g. E4-E*4, 58.68, -4.28)&lt;br/&gt;&lt;br/&gt;&lt;br/&gt;&amp;#45;&amp;#45;&amp;#45;-&lt;br/&gt; 2. Other ratios &amp;#45;- many within 17-odd limit&lt;br/&gt;&amp;#45;&amp;#45;&amp;#45;-&lt;br/&gt;&lt;br/&gt; 4:7 (968.83) &amp;#45;- Major sixth + QD (e.g. G3-E*4, 970.97, +2.14)&lt;br/&gt;&lt;br/&gt; 7:9 (435.08) &amp;#45;- Fourth - QD (e.g. G*4-C5, 437.22, +2.14)&lt;br/&gt;&lt;br/&gt; 7:12 (933.13) &amp;#45;- Minor seventh - QD (e.g. G*3-F4), at a pure 7:12.&lt;br/&gt;&lt;br/&gt; 9:14 (764.92) &amp;#45;- Fifth + QD (e.g. G4-D*5, 762.78, -2.14)&lt;br/&gt;&lt;br/&gt; 9:16 (996.09) &amp;#45;- Usual minor seventh (e.g. G4-F4, 991.81, -4.28)&lt;br/&gt;&lt;br/&gt; 6:11 (1049.36) &amp;#45;- Minor seventh + QD (e.g. G3-F*4, 1050.49, +1.13)&lt;br/&gt;&lt;br/&gt; 7:11 (782.49) &amp;#45;- Usual minor sixth (e.g. A3-F4, 783.62, +1.13)&lt;br/&gt;&lt;br/&gt; 8:11 (551.32) &amp;#45;- Fourth + QD (e.g. G3-C*4, 554.58, +3.27)&lt;br/&gt;&lt;br/&gt; 9:11 (347.41) &amp;#45;- Minor third + QD (e.g. G3-Bb*3, 346.39, -1.02)&lt;br/&gt;&lt;br/&gt; 8:13 (840.53) &amp;#45;- Minor sixth + QD (e.g. G3-Eb*3, 842.30, +1.77)&lt;br/&gt;&lt;br/&gt; 9:13 (636.62) &amp;#45;- Diminished fifth + QD (e.g. A3-Eb*4, 634.11, -2.51)&lt;br/&gt;&lt;br/&gt; 11:13 (289.21) &amp;#45;- Usual minor third (e.g. D3-F3, 287.71, -1.50)&lt;br/&gt;&lt;br/&gt; 11:14 (417.51) &amp;#45;- Usual major third (e.g. D3-F#3, 416.38, -1.13)&lt;br/&gt;&lt;br/&gt; 11:16 (648.68) &amp;#45;- Fifth - QD (e.g. F*3-C4, 645.42, -3.27)&lt;br/&gt;&lt;br/&gt; 11:18 (852.59) &amp;#45;- Major sixth - QD (e.g. G*4-E5, 853.61, +1.02)&lt;br/&gt;&lt;br/&gt; 11:21 (1119.46) &amp;#45;- Usual major seventh (e.g. F3-E4, 1120.48, +1.02)&lt;br/&gt;&lt;br/&gt; 12:17 (603.00) &amp;#45;- Augmented third + QD (e.g. Eb4-G#*4, 603.73, +0.73)&lt;br/&gt;&lt;br/&gt; 13:16 (359.47) &amp;#45;- Major third - QD (e.g. C*4-E4, 357.70, -1.77)&lt;br/&gt;&lt;br/&gt; 13:18 (563.38) &amp;#45;- Augmented fourth - QD (e.g. C*4-F#4, 565.89, +2.51)&lt;br/&gt;&lt;br/&gt; 13:21 (830.25) &amp;#45;- Usual augmented fifth (e.g. C4-G#4, 832.76, +2.51)&lt;br/&gt;&lt;br/&gt; 13:22 (910.79) &amp;#45;- Usual major sixth (e.g. G3-E4, 912.29, +1.50)&lt;br/&gt;&lt;br/&gt; 13:23 (987.75) &amp;#45;- Usual minor seventh (e.g. D4-C5, 991.81, +4.06)&lt;br/&gt;&lt;br/&gt; 13:24 (1061.43) &amp;#45;- Major seventh - QD (e.g. F*3-E4), 1061.80, +0.37)&lt;br/&gt;&lt;br/&gt; 14:17 (336.13) &amp;#45;- Usual augmented second (e.g. F4-G#4, 336.86, +0.73)&lt;br/&gt;&lt;br/&gt; 14:27 (1137.04) &amp;#45;- Octave - QD (e.g. F*4-F5, 1141.32, +4.28)&lt;br/&gt;&lt;br/&gt; 15:17 (216.69) &amp;#45;- Diminished third + QD (e.g. C#4-Eb*4, 217.72, +1.04)&lt;br/&gt;&lt;br/&gt; 16:21 (470.71) &amp;#45;- Major third + QD (e.g. C4-E*4, 475.06, +4.28)&lt;br/&gt;&lt;br/&gt; 16:23 (628.27) &amp;#45;- Usual augmented fourth (e.g. C4-F#4, 624.57, -3.70)&lt;br/&gt;&lt;br/&gt; 18:23 (424.36) &amp;#45;- Diminished fourth + QD (e.g. B4-Eb*5, 425.91, +1.55)&lt;br/&gt;&lt;br/&gt; 16:25 (772.63) &amp;#45;- Diminished fourth + QD (e.g. F#4-Bb*4, 774.09, +1.46)&lt;br/&gt;&lt;br/&gt; 17:20 (281.36) &amp;#45;- Augmented second - QD (e.g. F*4-G#4, 278.18, -3.18)&lt;br/&gt;&lt;br/&gt; 17:21 (365.83) &amp;#45;- Usual diminished fourth (e.g. F#4-Bb4, 367.24, +1.41)&lt;br/&gt;&lt;br/&gt; 17:28 (863.87) &amp;#45;- Usual diminished seventh (e.g. F#4-Eb4, 863.14, -0.73)&lt;br/&gt;&lt;br/&gt; 21:34 (834.17) &amp;#45;- Usual augmented fifth (e.g. F3-C#4, 832.76, +1.41)&lt;br/&gt;&lt;br/&gt; 28:51 (1038.08) &amp;#45;- Usual augmented sixth (e.g. Eb3-C#4, 1040.96, +2.87)&lt;br/&gt;&lt;br/&gt; 21:23 (157.49) &amp;#45;- Usual diminished third (e.g. C#4-Eb4, 159.04, +1.55)&lt;br/&gt;&lt;br/&gt; 21:26 (369.75) &amp;#45;- Usual diminished fourth (e.g. C#4-F4, 367.24, -1.51)&lt;br/&gt;&lt;br/&gt; 23:27 (277.59) &amp;#45;- Augmented second - QD (e.g. Eb*4-F#4, 278.18, +0.59)&lt;br/&gt;&lt;br/&gt; 26:33 (412.75) &amp;#45;- Usual major third (e.g. F4-A4, 416.38, +3.63)&lt;br/&gt;&lt;br/&gt; 28:33 (284.45) &amp;#45;- Usual minor third (e.g. E4-G4, 287.71, +3.27)&lt;br/&gt;&lt;br/&gt; 33:56 (915.55) &amp;#45;- Usual major sixth (e.g. G4-E5, 912.29, -3.27)&lt;br/&gt;&lt;/pre&gt;
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</style><pre class="text"> An interesting feature of tuning systems, as implemented on keyboards
 (conventional or alternative), is the [[keyboard mappings|mapping]] of pure or tempered
 ratios to positions on the keyboard layout.
&nbsp;
 Here I shall explore the mapping of approximate ratios, and especially
 of superparticular and other ratios within [[Harry Partch]]'s larger
 17-limit set, in the tuning system and keyboard arrangement I call
 Peppermint 24.
&nbsp;
 Peppermint 24 takes as its basis a [[Regular Temperaments|regular temperament]] mentioned in
 [[Erv Wilson|Ervin Wilson]]'s Scale Tree and described on the Tuning List by [[Keenan Pepper]],
 with a fifth of about 704.096 cents, and a precise ratio of
 [[Phi]], the Golden Section (~1.618) between the larger chromatic semitone
 (e.g. C-C#) at about 128.669 cents and the smaller diatonic semitone
 (e.g. C#-D) at about 79.522 cents.
&nbsp;
 In Peppermint 24, two regular 12-note chains of this temperament are
 placed at a distance of approximately 58.680 cents, so as to yield
 some pure ratios of 6:7 (~266.871 cents).
&nbsp;
 Here is a 24-note keyboard arrangement, with an asterisk (*) showing a
 note on the upper keyboard:
&nbsp;
     187.349  346.393              683.253    891.445 1050.488
       C#*      Eb*                   F#*       G#*     Bb*
  C*        D*          E*      F*        G*        A*       B*     C*
58.680   266.871    475.062  554.584   762.775  970.967  1179.158 1258.680
           7/6
-------------------------------------------------------------------------
     128.669  287.713              624.574    832.765 991.809
        C#      Eb                    F#         G#     Bb
  C         D           E       F          G         A        B     C
  0       208.191    416.382 495.904    704.096   912.287 1120.478 1200
&nbsp;
&nbsp;
 In the following catalogue of some ratio equivalents and mappings, I
 will focus on intervals no further from just than 8:9 or 9:16, which
 vary from their pure sizes by about 4.282 cents (twice the tempering
 of the fifth, at about 2.141 cents wide of 2:3).
&nbsp;
 Octave numbers appear in a MIDI-style notation, with C4 as middle C;
 just ratios and tempered equivalents are given values in cents, shown
 in parentheses, with tempered variations in cents also shown.
&nbsp;
 To describe the 58.68-cent interval between the two keyboards, whose
 addition or subtraction plays a role in obtaining or approximating
 many ratios, I shall the term &quot;quasi-diesis,&quot; or QD for short. This
 &quot;artificial&quot; diesis-like interval is actually somewhat larger than the
 natural diesis in the regular Wilson/Pepper temperament at about 49.15
 cents (12 tempered fifths less 7 pure octaves).
&nbsp;
 As this partial catalogue might suggest, many ratios of 2-3-7-9-11-13
 are represented quite accurately, with 14:17:21 and related ratios
 also closely approximated.
&nbsp;
&nbsp;
----
 1. Multiplex (n:1) and [[superparticular]] (n+1:n) intervals
----
&nbsp;
 1:2 (1200) -- This is the usual octave (e.g. F3-F4), at a pure 1:2.
&nbsp;
 2:3 (701.96) -- This is the usual fifth (e.g. F3-C4, 704.10, +2.14).
&nbsp;
 3:4 (498.04) -- Usual fourth (e.g. C4-F4, 495.90, -2.14).
&nbsp;
 6:7 (266.87) -- Major second + QD (e.g. D4-E*4), at a pure 6:7.
&nbsp;
 7:8 (231.17) -- Minor third - QD (e.g. C*4-Eb4, 229.03, -2.14)
&nbsp;
 8:9 (203.91) -- Usual major second (e.g. C4-D4, 208.19, +4.28)
&nbsp;
 11:12 (150.64) -- Major second - QD (e.g. C*4-D4, 149.51, -1.13)
&nbsp;
 12:13 (138.57) -- Minor second + QD (e.g. E4-F*4, 138.20, -0.37)
&nbsp;
 13:14 (128.30) -- Usual apotome (e.g. C4-C#4, 128.67, +0.37)
&nbsp;
 17:18 (98.95) -- Diminished third - QD (e.g. G#*4-Bb4, 100.36, -1.41)
&nbsp;
 21:22 (80.54) -- Usual minor second (e.g. E4-F4, 79.52, -1.02)
&nbsp;
 24:25 (70.67) -- Apotome - QD (e.g. E*4-Eb4, 69.99, -0.68)
&nbsp;
 27:28 (62.96) -- QD (e.g. E4-E*4, 58.68, -4.28)
&nbsp;
&nbsp;
----
 2. Other ratios -- many within 17-odd limit
----
&nbsp;
 4:7 (968.83) -- Major sixth + QD (e.g. G3-E*4, 970.97, +2.14)
&nbsp;
 7:9 (435.08) -- Fourth - QD (e.g. G*4-C5, 437.22, +2.14)
&nbsp;
 7:12 (933.13) -- Minor seventh - QD (e.g. G*3-F4), at a pure 7:12.
&nbsp;
 9:14 (764.92) -- Fifth + QD (e.g. G4-D*5, 762.78, -2.14)
&nbsp;
 9:16 (996.09) -- Usual minor seventh (e.g. G4-F4, 991.81, -4.28)
&nbsp;
 6:11 (1049.36) -- Minor seventh + QD (e.g. G3-F*4, 1050.49, +1.13)
&nbsp;
 7:11 (782.49) -- Usual minor sixth (e.g. A3-F4, 783.62, +1.13)
&nbsp;
 8:11 (551.32) -- Fourth + QD (e.g. G3-C*4, 554.58, +3.27)
&nbsp;
 9:11 (347.41) -- Minor third + QD (e.g. G3-Bb*3, 346.39, -1.02)
&nbsp;
 8:13 (840.53) -- Minor sixth + QD (e.g. G3-Eb*3, 842.30, +1.77)
&nbsp;
 9:13 (636.62) -- Diminished fifth + QD (e.g. A3-Eb*4, 634.11, -2.51)
&nbsp;
 11:13 (289.21) -- Usual minor third (e.g. D3-F3, 287.71, -1.50)
&nbsp;
 11:14 (417.51) -- Usual major third (e.g. D3-F#3, 416.38, -1.13)
&nbsp;
 11:16 (648.68) -- Fifth - QD (e.g. F*3-C4, 645.42, -3.27)
&nbsp;
 11:18 (852.59) -- Major sixth - QD (e.g. G*4-E5, 853.61, +1.02)
&nbsp;
 11:21 (1119.46) -- Usual major seventh (e.g. F3-E4, 1120.48, +1.02)
&nbsp;
 12:17 (603.00) -- Augmented third + QD (e.g. Eb4-G#*4, 603.73, +0.73)
&nbsp;
 13:16 (359.47) -- Major third - QD (e.g. C*4-E4, 357.70, -1.77)
&nbsp;
 13:18 (563.38) -- Augmented fourth - QD (e.g. C*4-F#4, 565.89, +2.51)
&nbsp;
 13:21 (830.25) -- Usual augmented fifth (e.g. C4-G#4, 832.76, +2.51)
&nbsp;
 13:22 (910.79) -- Usual major sixth (e.g. G3-E4, 912.29, +1.50)
&nbsp;
 13:23 (987.75) -- Usual minor seventh (e.g. D4-C5, 991.81, +4.06)
&nbsp;
 13:24 (1061.43) -- Major seventh - QD (e.g. F*3-E4), 1061.80, +0.37)
&nbsp;
 14:17 (336.13) -- Usual augmented second (e.g. F4-G#4, 336.86, +0.73)
&nbsp;
 14:27 (1137.04) -- Octave - QD (e.g. F*4-F5, 1141.32, +4.28)
&nbsp;
 15:17 (216.69) -- Diminished third + QD (e.g. C#4-Eb*4, 217.72, +1.04)
&nbsp;
 16:21 (470.71) -- Major third + QD (e.g. C4-E*4, 475.06, +4.28)
&nbsp;
 16:23 (628.27) -- Usual augmented fourth (e.g. C4-F#4, 624.57, -3.70)
&nbsp;
 18:23 (424.36) -- Diminished fourth + QD (e.g. B4-Eb*5, 425.91, +1.55)
&nbsp;
 16:25 (772.63) -- Diminished fourth + QD (e.g. F#4-Bb*4, 774.09, +1.46)
&nbsp;
 17:20 (281.36) -- Augmented second - QD (e.g. F*4-G#4, 278.18, -3.18)
&nbsp;
 17:21 (365.83) -- Usual diminished fourth (e.g. F#4-Bb4, 367.24, +1.41)
&nbsp;
 17:28 (863.87) -- Usual diminished seventh (e.g. F#4-Eb4, 863.14, -0.73)
&nbsp;
 21:34 (834.17) -- Usual augmented fifth (e.g. F3-C#4, 832.76, +1.41)
&nbsp;
 28:51 (1038.08) -- Usual augmented sixth (e.g. Eb3-C#4, 1040.96, +2.87)
&nbsp;
 21:23 (157.49) -- Usual diminished third (e.g. C#4-Eb4, 159.04, +1.55)
&nbsp;
 21:26 (369.75) -- Usual diminished fourth (e.g. C#4-F4, 367.24, -1.51)
&nbsp;
 23:27 (277.59) -- Augmented second - QD (e.g. Eb*4-F#4, 278.18, +0.59)
&nbsp;
 26:33 (412.75) -- Usual major third (e.g. F4-A4, 416.38, +3.63)
&nbsp;
 28:33 (284.45) -- Usual minor third (e.g. E4-G4, 287.71, +3.27)
&nbsp;
 33:56 (915.55) -- Usual major sixth (e.g. G4-E5, 912.29, -3.27)
&nbsp;</pre>

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