Delta
Delta may refer to:
- delta-N terminology, which indicates the difference between the numerator and the denominator of a ratio (aka the degree of epimoricity).
- a delta-d ratio (aka a superpartient ratio or an epimeric ratio), a ratio that is greater than 1 and is not superparticular.
- the delta scale, a nonoctave scale.
- the frequency difference represented by a dyad, especially in the context of delta-rational chords.