54/49
Interval information |
superpythagorean chroma
(Shannon, [math]\displaystyle{ \sqrt{nd} }[/math])
[sound info]
Zalzal's mujannab, the interval of 54/49 introduced by Mansour Zalzal, is between 11/10 and 10/9 in size, being 540/539 sharp of 11/10 and 245/243 flat of 10/9. It is the interval between 7/6 and 9/7. Tempering out 540/539 equates it with 11/10 and leads to swetismic chords. Occurring often in JI scales, it is one of the ways 11-limit harmony gets introduced into 7-limit scales.
It is also called the superpythagorean chromatic semitone[idiosyncratic term] or superpythagorean chroma since, in superpyth temperament, the minor third is 7/6, the major third is 9/7, and the difference between the two is 54/49.
Moving to exotempering, this can be tempered out, leading to the mujannabic temperament equating 7/6 and 9/7. However, it is usually better to temper out 25/24 instead for a similar structural effect.