Diesis
The diesis (/ˈdaɪəsɪs/ DY-ə-sis; plural dieses) most commonly refers to:
- 128/125;
- Any interval about that size. In particular, Zhea Erose defines it as, fairly broadly, any interval in the range 31 to 41 cents, or more narrowly 35 to 38 cents. When played in the E3-E5 range, those intervals allegedly tend to beat at the speed of typical human singing vibrato. Zhea considers 31edo and 34edo to be special for having an interval in this range.
Intervals with the word in the name:
- greater diesis, 648/625
- small diesis, aka magic comma
- minimal diesis, aka tetracot comma
- septimal diesis, 49/48
Normal diesis
The normal diesis (≈38.7¢) is an interval size measure defined as one step of 31edo.