Dinos comma
Interval information |
(Shannon, [math]\sqrt{nd}[/math])
531441/528125, the dinos comma, is a small 13-limit comma. It can be expressed as (3159/3125)/(2197/2187), (78732/78125)/(676/675), (9/5)/(325/243)2, (9/5)/(4/3)2/(325/324)2 and (81/80)/(325/324)2, among other expressions.
Temperaments
Tempering out this comma means equating a stack of two 325/243 (marveltwinous fourth) with 9/5. This comma is tempered out in some 13-limit temperaments, e.g. flattone extension. However, most of the case it is overshadowed by the 81/80. Tempering out this comma in its minimal prime subgroup of 3.5.13 leads to an unnamed temperament.
Etymology
The name "dinos" is proposed by Dummy index in 2024. It means: "miNOr Seventh is divided into 2 equal parts". The same argument holds for hemimean comma (3136/3125 = (9/5)/(75/56)2) and hewuermera comma (589824/588245 = (9/5)/(343/256)2), but the comma is no-twos and requires only one additional prime basis element (3.5 for 9/5 and additional .13 for the comma).