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Interval information
Ratio 676/675
Factorization 22 × 3-3 × 5-2 × 132
Monzo [2 -3 -2 0 0 2
Size in cents 2.5628932¢
Names island comma,
Color name 3oogg2, bithogu 2nd,
Bithogu comma
FJS name [math]\text{dd2}^{13,13}_{5,5}[/math]
Special properties square superparticular,
Tenney height (log2 nd) 18.7996
Weil height (log2 max(n, d)) 18.8018
Wilson height (sopfr (nd)) 49
Harmonic entropy
(Shannon, [math]\sqrt{nd}[/math])
~1.26016 bits
Comma size unnoticeable
S-expressions S26,
S13 / S15
open this interval in xen-calc

676/675, otherwise known as the island comma, or the parizeksma, is the difference between two 15/13's and a 4/3 perfect fourth, and also between 26/25 and 27/26. Tempering this comma out divides the perfect fourth into two equal halves, making island chords possible.


The name island comma was given by Mike Battaglia in 2011[1].

The 9-note MOS sounds like you're on some kind of tropical island off the coast of Barbados playing jubilant sun-music with the natives or something. More specifically, I feel like it takes the "island" feel of 5-equal and expands it out into diatonic and chromatic versions.

—Mike Battaglia

See also