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@endolith
Last active June 9, 2021 04:31
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List of chords in just intonation

Wikipedia's List of pitch intervals is great, but I can't find a single comprehensive list of just intonation triads/chord names anywhere, so I'll start making my own.

These are copied from Wikipedia or wherever. No guarantees of accuracy.

Several triads are illustrated in my consonance map.

Triads

2:3:4     power chord / fifth chord
3:5:7     "major triad of the Bohlen–Pierce scale"
4:5:6     major chord
5:6:7     perfect diminished chord
6:7:9     "The lowest numbers producing a minor triad in the harmonic series (McIntyre 2002)"
6:8:9     suspended fourth chord
8:9:12    suspended second chord
10:12:15  minor chord "the first occurrence of a minor triad in the harmonic series"
16:19:24  false minor triad?
16:20:25  augmented triad
27:32:40  supertonic triad?
45:54:64  diminished triad
54:64:243 Pythagorean minor triad
64:81:96  Pythagorean minor triad

Tetrads

3:5:7:9         "the primary tetrad in the Bohlen-Pierce tuning system"
3:5:9:15        "anomalous saturated suspension" http://x31eq.com/ass.htm
3:7:9:21        "anomalous saturated suspension"
4:5:6:7         harmonic seventh chord
4:5:6:18        major seventh chord
5:6:7:9         half-diminished seventh
8:9:10:12       mu major chord
8:10:12:15      major/major seventh chord
10:12:15:18     minor seventh
12:16:17:18     dream chord
20:25:30:36     dominant seventh chord
25:30:36:45     half-diminished seventh
40:48:60:75     minor/major seventh chord
80:100:125:144  augmented seventh chord

Pentads

4:5:6:7:9       Dominant ninth chord
8:10:12:14:17   Dominant minor ninth chord
20:25:30:36:48  Dominant seventh sharp ninth chord

Hexads

@ad8e
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ad8e commented Jun 30, 2019

8:10:12:15 major/major seventh chord

Should just have a single major?

4:5:6:18 major seventh chord

I couldn't find this. Maybe a typo?

@endolith
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@ad8e

hmm I don't know. this should be moved to xen.wiki anyway

@endolith
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endolith commented Jul 2, 2019

@ad8e
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ad8e commented Jul 2, 2019

Cool, thanks. Some of the high ratios are perceptually rounded to lower ratios, but I still found the resource useful.

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