261/256

{{Infobox Interval |Ratio = 261/256 |Name = 29-limit ~sixth tone (HEJI) |Color name = 29o1, tweno unison |Comma = yes |} 261/256, or the 29-limit ~sixth tone, is a 2.3.29 subgroup comma. It is the amount by which 29/16 (the 29th harmonic) exceeds the Pythagorean minor seventh (16/9). It is significant in Helmholtz-Ellis notation as the formal comma to translate a Pythagorean interval to a nearby 29-limit (prefix???) interval.