12:14:18:21

Chord information
Harmonics	12:14:18:21
Subharmonics	1/(21:18:14:12)
Intervals from root	1/1–7/6–3/2–7/4
Cents from root	0¢–267¢–702¢–969¢
Step intervals	7/6, 9/7, 7/6
Step cents	267¢, 435¢, 267¢
Prime limit	7
Genus	32⋅7 (63)
Intervallic odd limit	9
Otonal odd limit	21
Utonal odd limit	21
Consistent edos (d ≥ 2)	5edo, 22edo, 27edo, 31edo, …
	* 2 ≤ d < 4; 4 ≤ d < 8; * 8 ≤ d < 16; …

The swiss tetrad is a just 7-prime-limit, 9-odd-limit chord which is an ASS, or anomalous saturated suspension. In close position, it is 1-7/6-3/2-7/4 (12:14:18:21), with steps 7/6-9/7-7/6-8/7. Tempered versions of it have been called "subminor seventh chords" or "swiss sixth chords", so "swiss tetrad" splits the difference.

Ratio	1/1	7/6	3/2	7/4
Cents	0.00	266.87	701.96	968.83
Sound [info]