Chord Names
Triads shown here are the ones built from thirds, or from a second or fourth with a fifth.
Triads
| Triad |
Approx. JI |
Shorthand |
Name
|
| [0,3,6] |
21:24:28 |
Cf |
Semaphore
|
| [0,3,7] |
7/6/5 |
Cu |
Utonal Diminished
|
| [0,4,7] |
5:6:7 |
Co |
Otonal Diminished
|
| [0,3,8] |
7:8:10 |
Ct |
Triforce
|
| [0,4,8] |
35:42:50 |
Cd |
Diminished
|
| [0,5,8] |
10/8/7 |
Cw |
Wolf
|
| [0,2,9] |
18:20:27 |
C2 |
Suspended Second
|
| [0,3,9] |
6:7:9 |
Cs |
Subminor
|
| [0,4,9] |
6/5/4 |
Cm |
Minor
|
| [0,5,9] |
4:5:6 |
C |
Major
|
| [0,6,9] |
6:8:9 |
C4 |
Suspended Fourth
|
| [0,5,10] |
20:25:32 |
Ca |
Augmented
|
Tetradic and pentadic extensions have different intervals to use, depending on the top note of the triad in root position.
Tetradic and pentadic extensions (top note 6\15)
| Interval |
Approx. JI |
Shorthand |
Name
|
| 8\15 |
10/7 |
d |
Diminished Fifth
|
| 9\15 |
3/2 |
5 |
Perfect Fifth
|
| 10\15 |
8/5 |
m |
Minor Sixth
|
| 11\15 |
5/3 |
6 |
Major Sixth
|
| 12\15 |
7/4 |
h |
Harmonic Seventh
|
| 13\15 |
9/5 |
n |
Neutral Seventh
|
| 14\15 |
15/8 |
M |
Major Seventh
|
| 16\15 |
32/15 |
m |
Minor Ninth
|
Tetradic and pentadic extensions (top note 7\15)
| Interval |
Approx. JI |
Shorthand |
Name
|
| 9\15 |
3/2 |
5 |
Fifth
|
| 10\15 |
8/5 |
m |
Minor Sixth
|
| 11\15 |
5/3 |
6 |
Major Sixth
|
| 12\15 |
7/4 |
h |
Harmonic Seventh
|
| 13\15 |
9/5 |
n |
Neutral Seventh
|
| 14\15 |
15/8 |
M |
Major Seventh
|
| 16\15 |
32/15 |
m |
Minor Ninth
|
| 17\15 |
20/9 |
9 |
Major Ninth
|
Tetradic and pentadic extensions (top note 8\15)
| Interval |
Approx. JI |
Shorthand |
Name
|
| 10\15 |
8/5 |
m |
Minor Sixth
|
| 11\15 |
5/3 |
6 |
Major Sixth
|
| 12\15 |
7/4 |
h |
Harmonic Seventh
|
| 13\15 |
9/5 |
n |
Neutral Seventh
|
| 14\15 |
15/8 |
M |
Major Seventh
|
| X |
X |
7 |
Seventh
|
| 16\15 |
32/15 |
m |
Minor Ninth
|
| 17\15 |
20/9 |
9 |
Major Ninth
|
| 18\15 |
16/7 |
s |
Subminor Tenth
|
X: Extend the chord by the corresponding third in the chord (only applicable to triforce, diminished and wolf chords).
Tetradic and pentadic extensions (top note 9\15)
| Interval |
Approx. JI |
Shorthand |
Name
|
| 11\15 |
5/3 |
6 |
Sixth
|
| 12\15 |
7/4 |
h |
Harmonic Seventh
|
| 13\15 |
9/5 |
n |
Neutral Seventh
|
| 14\15 |
15/8 |
M |
Major Seventh
|
| X |
X |
7 |
Seventh
|
| 16\15 |
32/15 |
m |
Minor Ninth
|
| 17\15 |
20/9 |
M |
Major Ninth
|
| 18\15 |
16/7 |
s |
Subminor Tenth
|
| 19\15 |
12/5 |
m |
Minor Tenth
|
X: Add the interval which is the corresponding third up from the fifth (only applicable to subminor, minor and major chords).
Tetradic and pentadic extensions (top note 10\15)
| Interval |
Approx. JI |
Shorthand |
Name
|
| 12\15 |
7/4 |
6 |
Sixth
|
| 13\15 |
9/5 |
n |
Neutral Seventh
|
| 14\15 |
15/8 |
7 |
(Major) Seventh
|
| 16\15 |
32/15 |
m |
Minor Ninth
|
| 17\15 |
20/9 |
9 |
Major Ninth
|
| 18\15 |
16/7 |
s |
Subminor Tenth
|
| 19\15 |
12/5 |
m |
Minor Tenth
|
Examples
Assuming the root note is C,
[0,3,8,11] → Ct6
[0,4,8,12] → Cd7
[0,5,9,13] → Cn
Etc.
Links
15edo Triad and Tetrad Names in Xenpaper