Enharmonic
Two intervals or notes are enharmonically equivalent or simply enharmonic if they are mapped to the same number of steps in a tempered tuning system. For example, in 5edo, E and F are enharmonic because they are both mapped to 480 cents above C, and in 12edo, the augmented fourth and diminished fifth are enharmonic because they are both mapped to the semioctave of 600 cents.
Intervals can also be called enharmonic if they are close together but not exactly the same, for example if they are separated by a small comma, like the Pythagorean diminished fourth and Pythagorean major third. This extends to interval regions and categories, where interval categories that mostly overlap (like augmented thirds and perfect fourths) are considered "enharmonic".
Other than this, the term enharmonic has several meanings.
In regards to scales, see:
- A mos scale of 17 or 19 notes that is 7a 12b or 5a 12b with unspecified sizes for a and b (descended from 5L 2s such that diatonic enharmonic equivalents become distinct generic interval classes), which can be:
- The enharmonic genus, a genus in ancient Greek music theory containing scales with comma-sized steps
In regards to interval classification, see:
- Diatonic, chromatic, enharmonic, subchromatic, a hierarchy of interval classes, which explores the concept of enharmonicity from the perspective of the 12-note chromatic scale
- Enharmonic diesis, a diminished second (or an inverse diminished second)
- Enharmonic unison, an interval enharmonically equivalent to a unison