Comma and diesis: Difference between revisions

No edit summary
No edit summary
Line 17: Line 17:
The range of dieses largely overlaps with the range of [[quartertone]]s (between 40 and 60{{c}}, reasonably mapped to 1/24edo), which, according to systems that determine consonance in terms of proximity to simple just ratios, is one of the most dissonant interval regions. This also corresponds to an [[interseptimal]] interval range. However, quarter tones are still covered here to provide a resource for them in the same format as the other interval region pages.  
The range of dieses largely overlaps with the range of [[quartertone]]s (between 40 and 60{{c}}, reasonably mapped to 1/24edo), which, according to systems that determine consonance in terms of proximity to simple just ratios, is one of the most dissonant interval regions. This also corresponds to an [[interseptimal]] interval range. However, quarter tones are still covered here to provide a resource for them in the same format as the other interval region pages.  


In the diatonic scale, the analogous concepts are '''subchromatic''' and '''enharmonic''' steps. A subchromatic step does not change the interval category (for example, in most just notation systems, if you flatten the major third [[81/64]] by an [[81/80]] comma to produce [[5/4]], the latter is still considered a major third). Diatonically, subchromatic steps are '''perfect unisons (P1)''', and there are none that are not a unison in a rank-2 diatonic tuning. An enharmonic step changes the interval category to an enharmonic interval (for example, a major third to a diminished fourth, or a chromatic semitone to a diatonic semitone). Similarly, enharmonic steps are ascending or descending '''diminished seconds (d2)'''.  
In the diatonic scale, the analogous concepts are '''subchromatic''' and '''enharmonic''' steps. A subchromatic step (a "comma") does not change the interval category (for example, in most just notation systems, if you flatten the major third [[81/64]] by an [[81/80]] comma to produce [[5/4]], the latter is still considered a major third). Diatonically, subchromatic steps are '''perfect unisons (P1)''', and there are none that are not a unison in a rank-2 diatonic tuning. An enharmonic step (a "diesis", although this is controversial) changes the interval category to an enharmonic interval (for example, a major third to a diminished fourth, or a chromatic semitone to a diatonic semitone). Similarly, enharmonic steps are ascending or descending '''diminished seconds (d2)'''.  


== In just intonation ==
== In just intonation ==