Septimagic comma: Difference between revisions

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Created page with "{{Infobox interval | Ratio = 537824/531441 | Name = septimagic comma, magi comma | Color name = sz<sup>5</sup>4, saquinzo 4th | Comma = yes }} '''537824/531441''', the '''septimagic comma''' or '''magi comma''' is a no-fives 7-limit comma of measuring 20.7 cents. It is the difference between five 14/9s and two 3/1s. == Temperaments == Tempering out this comma gives the rank-3 '''septimagic temperament''' in the full 7-limit, and..."
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== Temperaments ==
== Temperaments ==
Tempering out this comma gives the rank-3 '''septimagic temperament''' in the full 7-limit, and the '''[[No-fives subgroup temperaments #Magi|magi temperament]]''' in its minimal prime subgroup of 2.3.7.
[[Tempering out]] this comma gives the rank-3 '''septimagic temperament''' in the full 7-limit, and the '''[[No-fives subgroup temperaments #Magi|magi temperament]]''' in its minimal prime subgroup of 2.3.7. Magi is the no-five restriction of the [[Magic|magic temperament]].
 
=== Septimagic ===
[[Subgroup]]: 2.3.5.7
 
[[Comma list]]: 537824/531441
 
{{Mapping|legend=1| 1 0 0 -1 | 0 5 0 12 | 0 0 1 0 }}
: Mapping generators: ~2, ~243/196, ~5
 
[[Optimal tuning]]s:
* [[WE]]: ~2 = 1199.822{{c}}, ~243/196 = 380.604{{c}}, ~5 = 2786.312{{c}}
* [[CWE]]: ~2 = 1200.000{{c}}, ~243/196 = 380.638{{c}}, ~5 = 2786.523{{c}}
 
{{Optimal ET sequence|legend=1| 19, 41, 104c, 126, 145, 167, 186 }}
 
[[Badness]] (Sintel): 11.758
 


== Etymology ==
== Etymology ==

Revision as of 02:02, 18 January 2026

Interval information
Ratio 537824/531441
Factorization 25 × 3-12 × 75
Monzo [5 -12 0 5
Size in cents 20.66952¢
Names septimagic comma,
magi comma
Color name sz54, saquinzo 4th
FJS name [math]\displaystyle{ \text{ddd4}^{7,7,7,7,7} }[/math]
Special properties reduced
Tenney norm (log2 nd) 38.0563
Weil norm (log2 max(n, d)) 38.0735
Wilson norm (sopfr(nd)) 81
Comma size small
Open this interval in xen-calc

537824/531441, the septimagic comma or magi comma is a no-fives 7-limit comma of measuring 20.7 cents. It is the difference between five 14/9s and two 3/1s.

Temperaments

Tempering out this comma gives the rank-3 septimagic temperament in the full 7-limit, and the magi temperament in its minimal prime subgroup of 2.3.7. Magi is the no-five restriction of the magic temperament.

Septimagic

Subgroup: 2.3.5.7

Comma list: 537824/531441

Mapping[1 0 0 -1], 0 5 0 12], 0 0 1 0]]

Mapping generators: ~2, ~243/196, ~5

Optimal tunings:

  • WE: ~2 = 1199.822 ¢, ~243/196 = 380.604 ¢, ~5 = 2786.312 ¢
  • CWE: ~2 = 1200.000 ¢, ~243/196 = 380.638 ¢, ~5 = 2786.523 ¢

Optimal ET sequence19, 41, 104c, 126, 145, 167, 186

Badness (Sintel): 11.758


Etymology

The word septimagic is a contraction of septimal magic into a single word.

See also