14:18:21

Chord information

Harmonics	14:18:21
Subharmonics	1/(9:7:6)
Intervals from root	1/1–9/7–3/2
Cents from root	0¢–435¢–702¢
Step intervals	9/7, 7/6
Step cents	435¢, 267¢
Color name	ru or r
Prime limit	7
Genus	32⋅7 (63)
Intervallic odd limit	9
Otonal odd limit	21
Utonal odd limit	9
Consistent edos (d ≥ 2)	5edo*, 14edo*, 17edo*, 19edo*, …
* 2 ≤ d < 4; ** 4 ≤ d < 8; *** 8 ≤ d < 16; …

14:18:21, the supermajor triad or septimal major triad, is a triad in the 7-limit sometimes used in place of a major triad. It is the inversion of 6:7:9, the septimal minor triad or subminor triad. The supermajor triad, unlike the 4:5:6 major triad, is utonal. Due to the more complex 9/7 interval above the root, it may sound less consonant than 6:7:9, similarly to how the 10:12:15 minor triad is generally considered less consonant than 4:5:6.

Edo approximations for 14:18:21 ▶
intervals: 9/7, 3/2 · ≤ 60edo, RMS rel. error ≤ 15%

	Edo	Steps	Cents (¢)	Absolute errors (¢)	RMS (¢)	RMS (%)
▶	8	0  3  5	0.00 450.00 750.00	0.00 +14.92 +48.04	20.08	13.39
▶	9	0  3  5	0.00 400.00 666.67	0.00 -35.08 -35.29	16.59	12.44
▶	14	0  5  8	0.00 428.57 685.71	0.00  -6.51 -16.24	6.67	7.79
▶	17	0  6 10	0.00 423.53 705.88	0.00 -11.55  +3.93	6.57	9.31
▶	19	0  7 11	0.00 442.11 694.74	0.00  +7.02  -7.22	5.81	9.20
▶	22	0  8 13	0.00 436.36 709.09	0.00  +1.28  +7.14	3.11	5.70
▶	27	0 10 16	0.00 444.44 711.11	0.00  +9.36  +9.16	4.37	9.82
▶	31	0 11 18	0.00 425.81 696.77	0.00  -9.28  -5.18	3.80	9.81
▶	36	0 13 21	0.00 433.33 700.00	0.00  -1.75  -1.96	0.88	2.63
▶	39	0 14 23	0.00 430.77 707.69	0.00  -4.31  +5.74	4.12	13.38
▶	41	0 15 24	0.00 439.02 702.44	0.00  +3.94  +0.48	1.75	5.99
▶	44	0 16 26	0.00 436.36 709.09	0.00  +1.28  +7.14	3.11	11.39
▶	46	0 17 27	0.00 443.48 704.35	0.00  +8.39  +2.39	3.53	13.54
▶	49	0 18 29	0.00 440.82 710.20	0.00  +5.73  +8.25	3.45	14.10
▶	50	0 18 29	0.00 432.00 696.00	0.00  -3.08  -5.96	2.43	10.13
▶	53	0 19 31	0.00 430.19 701.89	0.00  -4.90  -0.07	2.29	10.12
▶	55	0 20 32	0.00 436.36 698.18	0.00  +1.28  -3.77	2.14	9.83
▶	58	0 21 34	0.00 434.48 703.45	0.00  -0.60  +1.49	0.88	4.26
▶	60	0 22 35	0.00 440.00 700.00	0.00  +4.92  -1.96	2.89	14.45

Related chords

• 6:7:9 – its melodic inversion
• 70:90:105:126 or 1/(9:7:6:5), the subharmonic seventh chord – adds 9/5
• 28:36:42:49, a type of dominant seventh chord – adds 7/4
• 14:18:21:24 – adds 12/7
• 14:18:21:27 – adds 27/14