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Interval information
Ratio 128/99
Factorization 27 × 3-2 × 11-1
Monzo [7 -2 0 0 -1
Size in cents 444.77206¢
Names undecimal subfourth,
undecimal minor fourth,
Alpharabian paraminor fourth,
just paraminor fourth
Color name 1u4, lu 4th
FJS name [math]\text{P4}_{11}[/math]
Special properties reduced
Tenney height (log2 nd) 13.6294
Weil height (log2 max(n, d)) 14
Wilson height (sopfr (nd)) 31
Harmonic entropy
(Shannon, [math]\sqrt{n\cdot d}[/math])
~4.59058 bits
open this interval in xen-calc

In 11-limit just intonation, 128/99 is an undecimal subfourth measuring about 444.8¢. It is the inversion of 99/64, the undecimal superfifth. This interval is also known as the undecimal minor fourth through analogy with 11/8 being the "major fourth" as named by Ivan Wyschnegradsky, and can additionally be somewhat similarly dubbed the Alpharabian paraminor fourth or even the just paraminor fourth. It is distinguished from the simpler 22/17 by the twosquare comma.


This interval is especially close to the 10th step of 27edo.

See also