The swiss tetrad is a just 7-prime-limit, 9-odd-limit chord which is an 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.

Chord information
Harmonics 12:14:18:21
Subharmonics 1/(21:18:14:12)
Intervals from root 1/17/63/27/4
Cents from root 267¢702¢969¢
Step intervals 7/6, 9/7, 7/6
Step cents 267¢, 435¢, 267¢
Prime limit 7
Genus 327 (63)
Intervallic odd limit 9
Otonal odd limit 21
Utonal odd limit 21
Consistent edos (d ≥ 2) 5edo*, 22edo*, 27edo*, 31edo*, …
Ratio 1/1 7/6 3/2 7/4
Cents 0.00 266.87 701.96 968.83
Sound
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