70:84:105:120

70:84:105:120, the subharmonic sixth chord, is a tetrad in 7-limit harmony. It is the inverse of 4:5:6:7, the harmonic seventh chord. It can be considered the minor version of 4:5:6:7, and serves as the fundamental utonal consonance of the 7-odd-limit. On C, it can be notated as Cm(S6), where m is 5-limit minor and S is supermajor.

Chord information

Harmonics	70:84:105:120
Subharmonics	1/(12:10:8:7)
Intervals from root	1/1–6/5–3/2–12/7
Cents from root	0¢–316¢–702¢–933¢
Step intervals	6/5, 5/4, 8/7
Step cents	316¢, 386¢, 231¢
Color names	sub-6 or s6 gu ru-6 or g,r6
Prime limit	7
Genus	3⋅5⋅7 (105)
Intervallic odd limit	7
Otonal odd limit	105
Utonal odd limit	7
Consistent edos (d ≥ 2)	31edo*, 41edo*, 68edo*, 72edo*
* 2 ≤ d < 4; ** 4 ≤ d < 8; *** 8 ≤ d < 16; …

The subharmonic sixth chord may be modified to obtain the harmonic seventh chord by raising the 5/4 by 25/24 and the 7/4 by 49/48. The intervals 25/24 and 49/48 thus serve as chromas. It can also be modified by inflecting both 6/5 and 12/7 down by 36/35 to get the harmonic sixth chord 1–7/6–3/2–5/3.

Todo: add sound example

See also

• Its homonym 60:70:84:105 (a minor 7th flat-5th chord or half-diminished chord).