4096/3993
| Interval information |
Alpharabian paradiatonic semilimma,
Alpharabian semilimmic inframinor second
reduced subharmonic
(Shannon, [math]\sqrt{nd}[/math])
4096/3993, the Alpharabian paralimma or Alpharabian paradiatonic semilimma, is only just shy of being half of 256/243- the Pythagorean limma- being separated from the nearby 1331/1296, the interval forming the other part of the Pythagorean limma, by the nexus comma.
It is also notable for being one of only two quartertone intervals in the 11-limit- specifically the 2.3.11 subgroup- needed in order to add up to a familiar 9/8 whole tone. Specifically, it is the quartertone that forms the difference between the whole tone and a stack of three 33/32 quartertones, and can thus be regarded as being some sort of second- specifically, the Alpharabian semilimmic inframinor second, not to be confused with 8192/8019, the Alpharabian inframinor second, as the two intervals are only equated when 243/242, the rastma, is tempered out.
Remarkably, 4096/3993 is currently the simplest interval in terms of odd-limit that is known to result from stacking three identical quartertones with rational intervals and subtracting said stack from a 9/8 whole tone. Furthermore, although 38/37, 35/34, 32/31 and 28/27 are all simpler intervals that can be called "quarter tones" and can safely be regarded as some kind of second, subtracting any one of these intervals from 9/8 yields an interval that has a ratio lacking a cubed number in the numerator and or the denominator, and such an interval cannot be split into three equal quartertones with rational intervals.
Temperaments
Tempering out the paralimma in the 2.3.11 subgroup results in paralimmic temperament, where 3/1 is divided into 3 flat 16/11 generators.