List of 31edo chords

From Xenharmonic Wiki
Revision as of 16:56, 7 October 2026 by Sintel (talk | contribs) (Big rework, standardize notation, many smaller fixes)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search

This is an extensive list of chords that exist and can be utilized in 31edo.

Intervals are written in ups and downs notation. Harmonics are omitted if any of the harmonics are larger than 100.

The names, as well as the shorthand chord symbols are given only as a suggestion, as there is no single standardized system.

Triads

Standard triads are stacks of thirds, selected from vm3, m3, ~3, M3, or ^M3.

Standard triads JI ratios Harmonics 31edo steps Intervals Notation
Major 1/1 – 5/4 – 3/2 4:5:6 0, 10, 18 P1 M3 P5 I
Minor 1/1 – 6/5 – 3/2 10:12:15 0, 8, 18 P1 m3 P5 Im
Subminor 1/1 – 7/6 – 3/2 6:7:9 0, 7, 18 P1 vm3 P5 Is
Supermajor 1/1 – 9/7 – 3/2 14:18:21 0, 11, 18 P1 ^M3 P5 IS
Neutral 1/1 – 11/9 – 3/2 18:22:27 0, 9, 18 P1 ~3 P5 In
Augmented 1/1 – 5/4 – 25/16 16:20:25 0, 10, 20 P1 M3 A5 I+
Diminished 1/1 – 6/5 – 36/25 25:30:36 0, 8, 16 P1 m3 d5 Io
Harmonic diminished 1/1 – 6/5 – 7/5 5:6:7 0, 8, 15 P1 m3 vd5 Im(db5)
Subminor diminished 1/1 – 7/6 – 7/5 30:35:42 0, 7, 15 P1 vm3 vd5 Is(db5)
Septimal wolf major 1/1 – 9/7 – 32/21 21:27:32 0, 11, 19 P1 ^M3 ^5 IS(t5)
Septimal wolf minor 1/1 – 25/21 – 32/21 21:25:32 0, 8, 19 P1 m3 ^5 Im(t5)
Subfifth minor 1/1 – 6/5 – 22/15 15:18:22 0, 8, 17 P1 m3 v5 Im(d5)
Subfifth neutral 1/1 – 11/9 – 22/15 45:55:66 0, 9, 17 P1 ~3 v5 In(d5)
DRmaj 1/1 – 5/4 – 35/24 24:30:35 0, 10, 17 P1 M3 v5 I(d5)
DRmindim 1/1 – 7/6 – 35/24 24:28:35 0, 7, 17 P1 vm3 v5 Is(d5)
Orwell 1/1 – 7/6 – 11/8 24:28:33 0, 7, 14 P1 vm3 dd5 Is(bb5)
Squares 1/1 – 14/11 – 18/11 11:14:18 0, 11, 22 P1 ^M3 AA5 IS(x5)


Other triads JI ratios Harmonics 31edo steps Intervals Notation
Double diminished 1/1 – 8/7 – 10/7 7:8:10 0, 6, 16 P1 d3 d5 Io(bb3)
Major b5 1/1 – 5/4 – 10/7 28:35:40 0, 10, 16 P1 M3 d5 I(b5)
Minor augmented 1/1 – 32/27 – 14/9 27:32:42 0, 8, 20 P1 m3 A5 Im+
Double augmented 1/1 – 35/27 – 14/9 27:35:42 0, 12, 20 P1 A3 A5 I+(#3)
Doubly augmented 1/1 – 5/4 – 13/8 8:10:13 0, 10, 22 P1 M3 AA5 I(x5)
Sus4 1/1 – 4/3 – 3/2 6:8:9 0, 13, 18 P1 P4 P5 Isus4
Sus2 1/1 – 9/8 – 3/2 8:9:12 0, 5, 18 P1 M2 P5 Isus2
Sus(t4) 1/1 – 11/8 – 3/2 8:11:12 0, 14, 18 P1 ^4 P5 Isus(t4)
Sus(d4) 1/1 – 13/10 – 3/2 10:13:15 0, 12, 18 P1 v4 P5 Isus(d4)
Sus(t2) 1/1 – 8/7 – 3/2 14:16:21 0, 6, 18 P1 ^M2 P5 Isus(t2)
DRsus4 1/1 – 17/13 – 19/13 13:17:19 0, 12, 17 P1 v4 v5 Isus(d4)(d5)
DRsus2 1/1 – 19/17 – 19/13 0, 5, 17 P1 M2 v5 Isus2(d5)
Terrain triad 1/1 – 7/5 – 9/5 5:7:9 0, 15, 26 P1 vd5 m7 I(db5)m7
Harmonic shell 1/1 – 5/4 – 7/4 4:5:7 0, 10, 25 P1 M3 vm7 Ih7(no5)
Mothwellsmic shell 1/1 – 14/11 – 7/4 44:56:77 0, 11, 25 P1 ^M3 vm7 ISs7(no5)
Orgone triad 1/1 – 11/8 – 7/4 8:11:14 0, 14, 25 P1 ^4 vm7 Is7sus(t4)(no5)
Quartal 1/1 – 4/3 – 16/9 9:12:16 0, 13, 26 P1 P4 m7 Iq
Joan 1/1 – 11/8 – 15/8 8:11:15 0, 14, 28 P1 ^4 M7 IJ

Notes: DR means Delta-rational.


Tetrads

These tetrads are split into a few general categories.

Basic tetrads JI ratios Harmonics 31edo steps Intervals Notation
Major seven 1/1 – 5/4 – 3/2 – 15/8 8:10:12:15 0, 10, 18, 28 P1 M3 P5 M7 IM7
Harmonic seven 1/1 – 5/4 – 3/2 – 7/4 4:5:6:7 0, 10, 18, 25 P1 M3 P5 vm7 Ih7
Minor seven 1/1 – 6/5 – 3/2 – 9/5 10:12:15:18 0, 8, 18, 26 P1 m3 P5 m7 Im7
Utonal tetrad 1/1 – 6/5 – 3/2 – 12/7 0, 8, 18, 24 P1 m3 P5 ^M6 ImS6
Subminor seven 1/1 – 7/6 – 3/2 – 7/4 12:14:18:21 0, 7, 18, 25 P1 vm3 P5 vm7 Is7
Undecimal tetrad 1/1 – 7/6 – 3/2 – 11/6 6:7:9:11 0, 7, 18, 27 P1 vm3 P5 ~7 Isn7
Supermajor seven 1/1 – 9/7 – 3/2 – 27/14 14:18:21:27 0, 11, 18, 29 P1 ^M3 P5 ^M7 IS7
9-over tetrad 1/1 – 9/7 – 3/2 – 9/5 0, 11, 18, 26 P1 ^M3 P5 m7 ISm7
Neutral seven 1/1 – 11/9 – 3/2 – 11/6 18:22:27:33 0, 9, 18, 27 P1 ~3 P5 ~7 In7


Other basic tetrads JI ratios Harmonics 31edo steps Intervals Notation
Lynch neutral 1/1 – 3/2 – 11/6 – 11/4 12:18:22:33 0, 18, 27, 45 P1 P5 ~7 ^11 In7t11(no3)
Neutral minor Seven 1/1 – 27/22 – 3/2 – 9/5 0, 9, 18, 26 P1 ~3 P5 m7 Inm7
Neutral major tetrad 1/1 – 27/22 – 3/2 – 27/16 0, 9, 18, 23 P1 ~3 P5 M6 InM6
Subminor major tetrad 1/1 – 7/6 – 3/2 – 5/3 6:7:9:10 0, 7, 18, 23 P1 vm3 P5 M6 IsM6
Dominant 1/1 – 5/4 – 3/2 – 9/5 20:25:30:36 0, 10, 18, 26 P1 M3 P5 m7 I7
Mothwellsmic dominant 1/1 – 14/11 – 3/2 – 7/4 44:56:66:77 0, 11, 18, 25 P1 ^M3 P5 vm7 ISs7
Subminor supermajor Seven 1/1 – 7/6 – 3/2 – 21/11 0, 7, 18, 29 P1 vm3 P5 ^M7 IsS7
Augmented seven 1/1 – 5/4 – 25/16 – 7/4 16:20:25:28 0, 10, 20, 25 P1 M3 A5 vm7 Ih7(#5)
Half augmented 1/1 – 5/4 – 25/16 – 15/8 16:20:25:30 0, 10, 20, 28 P1 M3 A5 M7 IM7(#5)
Fully augmented 1/1 – 5/4 – 25/16 – 125/64 0, 10, 20, 30 P1 M3 A5 A7 I+7
Half diminished 1/1 – 6/5 – 36/25 – 9/5 25:30:36:45 0, 8, 16, 26 P1 m3 d5 m7 Im7(b5)
Fully diminished 1/1 – 25/21 – 10/7 – 12/7 21:25:30:36 0, 8, 16, 24 P1 m3 d5 d7 Io7
Harmonic half diminished 1/1 – 6/5 – 7/5 – 9/5 5:6:7:9 0, 8, 15, 26 P1 m3 vd5 m7 Im7(db5)
Harmonic fully diminished 1/1 – 6/5 – 7/5 – 17/10 10:12:14:17 0, 8, 15, 24 P1 m3 vd5 d7 Io7(db5)
Subminor half diminished 1/1 – 7/6 – 7/5 – 7/4 0, 7, 15, 25 P1 vm3 vd5 vm7 Is7(db5)
Augmented 3&7 1/1 – 13/10 – 3/2 – 39/20 20:26:30:39 0, 12, 18, 30 P1 A3 P5 A7 I(#3, #7)
Diminished 3&7 1/1 – 15/13 – 3/2 – 45/26 26:30:39:45 0, 6, 18, 24 P1 d3 P5 d7 I(bb3, bb7)
Doubly augmented major seven 1/1 – 5/4 – 13/8 – 15/8 8:10:13:15 0, 10, 22, 28 P1 M3 AA5 M7 IM7(x5)
Supermajor seven augmented 1/1 – 9/7 – 11/7 – 27/14 14:18:22:27 0, 11, 20, 29 P1 ^M3 A5 ^M7 IS7(#5)


Fifth-contained tetrads JI ratios Harmonics 31edo steps Intervals Notation
Mu chord 1/1 – 9/8 – 5/4 – 3/2 8:9:10:12 0, 5, 10, 18 P1 M2 M3 P5 I(add2)
Nu chord 1/1 – 6/5 – 4/3 – 3/2 30:36:40:45 0, 8, 13, 18 P1 m3 P4 P5 Im(add4)
Subminor tetrad 1/1 – 7/6 – 4/3 – 3/2 6:7:8:9 0, 7, 13, 18 P1 vm3 P4 P5 Is(add4)
Supermajor tetrad 1/1 – 9/8 – 9/7 – 3/2 56:63:72:84 0, 5, 11, 18 P1 M2 ^M3 P5 IS(add2)
Super second tetrad 1/1 – 8/7 – 9/7 – 3/2 14:16:18:21 0, 6, 11, 18 P1 ^M2 ^M3 P5 IS(add t2)
Sub fourth tetrad 1/1 – 7/6 – 21/16 – 3/2 48:56:63:72 0, 7, 12, 18 P1 vm3 v4 P5 Is(add d4)
Sus 2/4 1/1 – 10/9 – 4/3 – 3/2 18:20:24:27 0, 5, 13, 18 P1 M2 P4 P5 Isus(2/4)
Add^4 1/1 – 5/4 – 11/8 – 3/2 8:10:11:12 0, 10, 14, 18 P1 M3 ^4 P5 I(add t4)
Minor addv2 1/1 – 12/11 – 6/5 – 3/2 0, 4, 8, 18 P1 ~2 m3 P5 Im(add d2)


Split chords JI ratios Harmonics 31edo steps Intervals Notation
Split chord 1/1 – 6/5 – 5/4 – 3/2 20:24:25:30 0, 8, 10, 18 P1 m3 M3 P5 IMm3
Septimal split chord 1/1 – 33/28 – 9/7 – 3/2 28:33:36:42 0, 7, 11, 18 P1 vm3 ^M3 P5 ISs3
Yellow/blue split chord 1/1 – 7/6 – 5/4 – 3/2 12:14:15:18 0, 7, 10, 18 P1 vm3 M3 P5 IMs3
Green/red split chord 1/1 – 6/5 – 9/7 – 3/2 0, 8, 11, 18 P1 m3 ^M3 P5 ISm3
Wolf split chord 1/1 – 25/21 – 9/7 – 32/21 21:25:27:32 0, 8, 11, 19 P1 m3 ^M3 ^5 ISm3(t5)
Squares split chord 1/1 – 27/22 – 14/11 – 18/11 22:27:28:36 0, 9, 11, 22 P1 ~3 ^M3 AA5 ISn3(#5)
DR split chord 1/1 – 7/6 – 5/4 – 35/24 24:28:30:35 0, 7, 10, 17 P1 vm3 M3 v5 IMs3(d5)


Harmonic subsets JI ratios Harmonics 31edo steps Intervals Notation
h9 shell 1/1 – 5/4 – 7/4 – 9/4 4:5:7:9 0, 10, 25, 36 P1 M3 vm7 M9 Ih9(no5)
Add11 shell 1/1 – 5/4 – 7/4 – 11/4 4:5:7:11 0, 10, 25, 45 P1 M3 vm7 ^11 Ih7t11(no5)
Quintal neutral 1/1 – 3/2 – 9/4 – 11/4 4:6:9:11 0, 18, 36, 45 P1 P5 M9 ^11 I59t11
Altered 13 shell 1/1 – 5/4 – 7/4 – 13/4 4:5:7:13 0, 10, 25, 53 P1 M3 vm7 ~13 Ih7d13(no5)
Add-13 1/1 – 5/4 – 3/2 – 13/4 4:5:6:13 0, 10, 18, 53 P1 M3 P5 ~13 I(add d13)
Altered 17 shell 1/1 – 5/4 – 7/4 – 17/8 8:10:14:17 0, 10, 25, 34 P1 M3 vm7 m9 Ih7b9(no5)
Altered 19 shell 1/1 – 5/4 – 7/4 – 19/8 8:10:14:19 0, 10, 25, 39 P1 M3 vm7 m10 Ih7b10(no5)


Misc tetrads JI ratios Harmonics 31edo steps Intervals Notation
h7#9 shell 1/1 – 5/4 – 7/4 – 7/3 12:15:21:28 0, 10, 25, 38 P1 M3 vm7 A9 Ih7#9(no5)
h7db9 shell 1/1 – 5/4 – 7/4 – 25/12 12:15:21:25 0, 10, 25, 33 P1 M3 vm7 vm9 Ih7db9(no5)
h7d9 shell 1/1 – 5/4 – 7/4 – 35/16 16:20:28:35 0, 10, 25, 35 P1 M3 vm7 ~9 Ih7d9(no5)
DRmaj 1/1 – 9/8 – 5/4 – 35/24 24:27:30:35 0, 5, 10, 17 P1 M2 M3 v5 I(add 2, d5)
DRmin 1/1 – 7/6 – 32/21 – 12/7 42:49:64:72 0, 7, 19, 24 P1 vm3 ^5 ^M6 IsS6(t5)
DRmindim 1/1 – 7/6 – 16/11 – 56/33 0, 7, 17, 24 P1 vm3 v5 ^M6 IsS6(d5)
DRsus 1/1 – 9/8 – 21/16 – 35/24 48:54:63:70 0, 5, 12, 17 P1 M2 v4 v5 Isus(2/d4)(d5)
Leading DRsus2 1/1 – 19/17 – 19/13 – 19/10 0, 5, 17, 29 P1 M2 v5 ^M7 IS7sus2(d5)
Mothwellsmic dominant #9 shell 1/1 – 14/11 – 7/4 – 7/3 0, 11, 25, 38 P1 ^M3 vm7 A9 ISs7#9(no5)
Orgone add9 1/1 – 11/8 – 7/4 – 9/4 8:11:14:18 0, 14, 25, 36 P1 ^4 vm7 M9 Ih9sus(t4)(no5)
Greeley over-3 1/1 – 7/6 – 5/3 – 11/6 – (13/6) 6:7:10:11:(13) 0, 7, 23, 27, (35) P1 vm3 M6 ~7 (~9) IsM6n7(no5)


Other linear tetrads JI ratios Harmonics 31edo steps Intervals Notation
Slendric tetrad 1/1 – 8/7 – 55/42 – 3/2 42:48:55:63 0, 6, 12, 18 P1 ^M2 v4 P5 Isus(t2/d4)
Miracle cluster 1/1 – 14/13 – 15/13 – 16/13 13:14:15:16 0, 3, 6, 9 P1 m2 ^M2 ~3 I(13:14:15:16)
Orwell tetrad 1/1 – 7/6 – 11/8 – 77/48 48:56:66:77 0, 7, 14, 21 P1 vm3 ^4 m6 IO

Pentads

Main ninth chords JI ratios Harmonics 31edo steps Intervals Notation
Major nine 1/1 – 5/4 – 3/2 – 15/8 – 9/4 8:10:12:15:18 0, 10, 18, 28, 36 P1 M3 P5 M7 M9 IM9
Harmonic nine 1/1 – 5/4 – 3/2 – 7/4 – 9/4 4:5:6:7:9 0, 10, 18, 25, 36 P1 M3 P5 vm7 M9 Ih9
Minor nine 1/1 – 6/5 – 3/2 – 9/5 – 9/4 20:24:30:36:45 0, 8, 18, 26, 36 P1 m3 P5 m7 M9 Im9
Subminor nine 1/1 – 7/6 – 3/2 – 7/4 – 9/4 12:14:18:21:27 0, 7, 18, 25, 36 P1 vm3 P5 vm7 M9 Is9
Supermajor nine 1/1 – 9/7 – 3/2 – 27/14 – 9/4 28:36:42:54:63 0, 11, 18, 29, 36 P1 ^M3 P5 ^M7 M9 IS9
9-over pentad 1/1 – 9/7 – 3/2 – 9/5 – 9/4 0, 11, 18, 26, 36 P1 ^M3 P5 m7 M9 IS9b7
Neutral pentad 1/1 – 11/9 – 3/2 – 11/6 – 9/4 36:44:54:66:81 0, 9, 18, 27, 36 P1 ~3 P5 ~7 M9 In9


Other main pentads JI ratios Harmonics 31edo steps Intervals Notation
Major 6/9 1/1 – 5/4 – 3/2 – 5/3 – 9/4 12:15:18:20:27 0, 10, 18, 23, 36 P1 M3 P5 M6 M9 I6/9
Minor 7/11 1/1 – 6/5 – 3/2 – 9/5 – 27/10 10:12:15:18:27 0, 8, 18, 26, 44 P1 m3 P5 m7 P11 Im7/11
Dominant nine 1/1 – 5/4 – 3/2 – 9/5 – 9/4 20:25:30:36:45 0, 10, 18, 26, 36 P1 M3 P5 m7 M9 I9
Tridecimal pentad 1/1 – 7/6 – 3/2 – 11/6 – 13/6 6:7:9:11:13 0, 7, 18, 27, 35 P1 vm3 P5 ~7 ~9 Isn7d9
Subminor 6/9 1/1 – 7/6 – 3/2 – 5/3 – 9/4 12:14:18:20:27 0, 7, 18, 23, 36 P1 vm3 P5 M6 M9 IsM6/9
Subminor 7/11 1/1 – 7/6 – 3/2 – 7/4 – 21/8 24:28:36:42:63 0, 7, 18, 25, 43 P1 vm3 P5 vm7 v11 Is7d11
Sub neutral 11 1/1 – 7/6 – 3/2 – 11/6 – 11/4 12:14:18:22:33 0, 7, 18, 27, 45 P1 vm3 P5 ~7 ^11 Isn7t11
Fully augmented #9 1/1 – 5/4 – 25/16 – 125/64 – 75/32 0, 10, 20, 30, 38 P1 M3 A5 A7 A9 I+7#9


Altered pentads JI ratios Harmonics 31edo steps Intervals Notation
Harmonic #9 1/1 – 5/4 – 3/2 – 7/4 – 7/3 12:15:18:21:28 0, 10, 18, 25, 38 P1 M3 P5 vm7 A9 Ih7#9
Harmonic db9 1/1 – 5/4 – 3/2 – 7/4 – 25/12 12:15:18:21:25 0, 10, 18, 25, 33 P1 M3 P5 vm7 vm9 Ih7db9
Altered 13 1/1 – 5/4 – 3/2 – 7/4 – 13/4 4:5:6:7:13 0, 10, 18, 25, 53 P1 M3 P5 vm7 ~13 Ih7d13
Altered 13 #9 shell 1/1 – 5/4 – 7/4 – 7/3 – 13/4 12:15:21:28:39 0, 10, 25, 38, 53 P1 M3 vm7 A9 ~13 Ih7#9d13(no5)


Split pentads JI ratios Harmonics 31edo steps Intervals Notation
Sub seventh split 1/1 – 7/6 – 5/4 – 3/2 – 7/4 12:14:15:18:21 0, 7, 10, 18, 25 P1 vm3 M3 P5 vm7 IMs3s7
Major seventh split 1/1 – 7/6 – 5/4 – 3/2 – 15/8 24:28:30:36:45 0, 7, 10, 18, 28 P1 vm3 M3 P5 M7 IMs3M7
Major sixth split 1/1 – 7/6 – 5/4 – 3/2 – 5/3 12:14:15:18:20 0, 7, 10, 18, 23 P1 vm3 M3 P5 M6 IMs3M6
Minor seventh split 1/1 – 6/5 – 9/7 – 3/2 – 9/5 0, 8, 11, 18, 26 P1 m3 ^M3 P5 m7 ISm3m7
Super seventh split 1/1 – 6/5 – 9/7 – 3/2 – 27/14 0, 8, 11, 18, 29 P1 m3 ^M3 P5 ^M7 ISm3S7
Super sixth split 1/1 – 6/5 – 9/7 – 3/2 – 12/7 0, 8, 11, 18, 24 P1 m3 ^M3 P5 ^M6 ISm3S6


Harmonic pentads JI ratios Harmonics 31edo steps Intervals Notation
Orwell harmonic 1/1 – 5/4 – 3/2 – 7/4 – 11/4 4:5:6:7:11 0, 10, 18, 25, 45 P1 M3 P5 vm7 ^11 Ih7t11
Mohajira harmonic 1/1 – 5/4 – 3/2 – 9/4 – 11/4 4:5:6:9:11 0, 10, 18, 36, 45 P1 M3 P5 M9 ^11 Ih11(no7)
Tutone harmonic 1/1 – 5/4 – 7/4 – 9/4 – 11/4 4:5:7:9:11 0, 10, 25, 36, 45 P1 M3 vm7 M9 ^11 Ih11(no5)
Squares harmonic 1/1 – 3/2 – 7/4 – 9/4 – 11/4 4:6:7:9:11 0, 18, 25, 36, 45 P1 P5 vm7 M9 ^11 Ih11(no3)
Over-5 harmonic 1/1 – 6/5 – 7/5 – 9/5 – 11/5 5:6:7:9:11 0, 8, 15, 26, 35 P1 m3 vd5 m7 ~9 Im7d9(db5)
Miracle harmonic 1/1 – 5/4 – 7/4 – 13/4 – 17/4 4:5:7:13:17 0, 10, 25, 53, 65 P1 M3 vm7 ~13 m16 Ih7d13b16(no5)
A-Team harmonic 1/1 – 5/4 – 13/4 – 17/4 – 19/4 4:5:13:17:19 0, 10, 53, 65, 70 P1 M3 ~13 m16 m17 IMd13b16b17(no5)
Joan sharp harmonic 1/1 – 7/4 – 13/4 – 17/4 – 19/4 4:7:13:17:19 0, 25, 53, 65, 70 P1 vm7 ~13 m16 m17 Is7d13b16b17(no3, no5)
Joan flat harmonic 1/1 – 7/4 – 9/4 – 11/4 – 15/4 4:7:9:11:15 0, 25, 36, 45, 59 P1 vm7 M9 ^11 M14 I9s7t11M14(no3, no5)
Greeley harmonic 1/1 – 7/6 – 5/3 – 11/6 – 13/6 6:7:10:11:13 0, 7, 23, 27, 35 P1 vm3 M6 ~7 ~9 IsM6n7d9(no5)


Other linear pentads JI ratios Harmonics 31edo steps Intervals Notation
Slendric pentad 1/1 – 8/7 – 55/42 – 3/2 – 12/7 42:48:55:63:72 0, 6, 12, 18, 24 P1 ^M2 v4 P5 ^M6 IS6sus(t2, d4)
Miracle cluster 1/1 – 14/13 – 15/13 – 16/13 – 17/13 13:14:15:16:17 0, 3, 6, 9, 12 P1 m2 ^M2 ~3 v4 I(13:14:15:16:17)
Orwell pentad 1/1 – 7/6 – 11/8 – 77/48 – 15/8 48:56:66:77:90 0, 7, 14, 21, 28 P1 vm3 ^4 m6 M7 IOM7


Other extended chords

JI ratios Harmonics 31edo steps Intervals Notation Comments
Undecimal hexad 1/1 – 5/4 – 3/2 – 7/4 – 9/4 – 11/4 4:5:6:7:9:11 0, 10, 18, 25, 36, 45 P1 M3 P5 vm7 M9 ^11 Ih11 The holy grail chord, a rich complex sound made up of the main harmonics in 31.
Novemdecimal hexad 1/1 – 5/4 – 7/4 – 13/4 – 17/4 – 19/4 4:5:7:13:17:19 0, 10, 25, 53, 65, 70 P1 M3 vm7 ~13 m16 m17 Ih7d13b16b17(no5) All the sharp harmonics on a basic harmonic shell, works decently due to the extreme accuracy of the 13:17:19.
? 1/1 – 7/6 – 3/2 – 11/6 – 5/2 – 10/3 6:7:9:11:15:20 0, 7, 18, 27, 41, 54 P1 vm3 P5 ~7 M10 M13 Isn7(10, 13) Standard undecimal triad but with some quartal flavor in the tensions, adds a good unique sound that can be sort of hard to add with this tetrad.
? 1/1 – 5/4 – 3/2 – 15/8 – 11/4 – 33/8 8:10:12:15:22:33 0, 10, 18, 28, 45, 63 P1 M3 P5 M7 ^11 ^15 Imaj7t11t15 Zhea Erose Chord, can also be used with a harmonic seventh to avoid the subfifth dissonance.
Rast minor parent chord 1/1 – 6/5 – 3/2 – 9/5 – 11/5 – 27/10 – 33/10 10:12:15:18:22:27:33 0, 8, 18, 26, 35, 44, 53 P1 m3 P5 m7 ~9 P11 ~13 Im7/11n9n13 Subset chords excluding one of the tensions may be preferable to avoid chains of neutral thirds.
Graham hexad 1/1 – 5/4 – 3/2 – 7/4 – 7/3 – 11/4 12:15:18:21:28:33 0, 10, 18, 25, 38, 45 P1 M3 P5 vm7 A9 ^11 Ih11#9 The whole thing works as a chord but just using subsets works well too, the shell voicing is often a better choice.
? 1/1 – 6/5 – 3/2 – 12/7 – 16/7 – 8/3 0, 8, 18, 24, 37, 44 P1 m3 P5 ^M6 ^M9 P11 ImS69add11 Analog of a minor 69 type chord. Shows why utonal chords don’t always work well with tensions , with high complexity for a simple base tetrad.
? 1/1 – 5/4 – 3/2 – 7/4 – 21/8 – 63/16 16:20:24:28:42:63 0, 10, 18, 25, 43, 61 P1 M3 P5 vm7 v11 v15 Ih7d11d15 Subminor ninth and suboctave add dissonance, but strong fifths between 7, 11, and 15 add structure that allows the chord to function.
? 1/1 – 5/4 – 7/4 – 75/32 – 25/8 – 125/32 0, 10, 25, 38, 51, 61 P1 M3 vm7 A9 vm13 v15 Ih7#9db13d15(no5) Extension of a standard jazz chord, with the 3:4:5 on top providing stability to balance the suboctave dissonance.
? 1/1 – 5/4 – 25/16 – 15/8 – 7/3 – 35/12 0, 10, 20, 28, 38, 48 P1 M3 A5 M7 A9 AA11 Imaj7+(#9, x11) An interesting chord, pretty much as many major thirds as you can have without any augmented sevenths.
Mothra[6] 5 parent chord 1/1 – 7/6 – 32/21 – 7/4 – 16/7 – 8/3 0, 7, 19, 25, 37, 44 P1 vm3 ^5 vm7 ^M9 P11 Is7/11t9(t5) Subsets work well too, emphasizes the mothra sound through the superfifths and subfourths present.