7777/7776

This page presents a novelty topic. It may contain ideas which are less likely to find practical applications in music, or numbers or structures that are arbitrary or exceedingly small, large, or complex. Novelty topics are often developed by a single person or a small group. As such, this page may also contain idiosyncratic terms, notation, or conceptual frameworks.

7777/7776, the pulsar comma or power-of-six repdigit comma is an unnoticeable comma of 0.223 cents, and it is a part of 101-limit just intonation.

Interval information

Ratio	7777/7776
Subgroup monzo	2.3.7.11.101 [-5 -5 1 1 1⟩
Size in cents	0.2226238¢
Name	pulsar comma
Color name	101o1oz2, Fifiwolozo comma
FJS name	[math]\displaystyle{ \text{d2}^{7,11,101} }[/math]
Special properties	superparticular, reduced
Tenney norm (log2 nd)	25.8498
Weil norm (log2 max(n, d))	25.85
Wilson norm (sopfr(nd))	144
Comma size	unnoticeable
Open this interval in xen-calc

The comma derives from the resemblance of a perfect power of 6, 7776, to a decimal repdigit number 7777. It is the difference between a stack of five 6/1's and 7, 11, and 101 harmonics stacked, or when octave-reduced, between 7/4, 11/8, and 101/64 and the Pythagorean major seventh, 243/128. It is also the difference between 404/243 and 128/77.

The name origin is the following: power-of-six repdigit – psr, which is the astronomical shortening for pulsars.

Temperaments

Some of the edos which support pulsar temperaments in its 2.3.7.11.101-subgroup patent vals are 135, 207, 342, 477, 836, 877, 971, 1012, and 1147.