Frameshift comma
The Frameshift comma is an unnoticeable 11-limit comma- specifically of the 2.3.11 subgroup- with a complicated ratio of 22876792454961/22866405883904, and a size of roughly 0.79 cents. It is the interval separating the Rastma from the Pythrabian comma as well as the amount by which an octave-reduced stack of three 11/8 intervals falls short of a stack of four apotomes. Since both the Rastmic and Pythrabian temperaments are ways of conceptualizing how the 11-prime relates to the 3-prime within the 2.3.11 subgroup, that means that these two distinct frameworks for viewing the 11-prime relative to the 3-prime become linked when 22876792454961/22866405883904 is tempered out- hence the name "Frameshift" comma- a name which is even more appropriate in light of the fact that when one tempers out this comma, one can effectively modulate to 11/8 though a series of five, rather typical-sounding semitone-based motions- thus shifting a listener's perception of pitch relations such that the modulation sounds in tune. Naturally, tempering out this comma results in some form of Frameshift microtemperament.
| Interval information |