243/242: Difference between revisions

'''243/242''', the '''rastma''' or the '''neutral third comma''', is an [[11-limit]] (also 2.3.11 subgroup) comma with a value of roughly 7.1 [[cent]]s. It is significant in Just Intonation as the amount by which a stack of two [[11/9]] neutral thirds fall short of [[3/2]] just perfect fifth, by which a stack of two [[33/32]] quartertones falls short of an [[2187/2048|apotome (2187/2048)]] as well as the difference between [[11/9]] and [[27/22]], and, the difference between [[45/44]] and [[55/54]]. The last makes the theory where the rastma serves as the [[Diatonic, Chromatic, Enharmonic, Subchromatic|subchroma]] that separates greater and lesser 11-limit chromas – a theory that becomes especially useful when one works extensively with high-fidelity renditions of the 11-limit.