Form

A form is a framework for conceptualizing the intervals in a tuning system, where the N-form contains N interval categories within the equave.

A tuning system is in the N-form if it is describable by a (usually soft, at minimum Rothenberg proper) scale of cardinality N, such that N-edo is the simplest edo that gives a sense of the categorical distinctions being made by the structure. For an example, meantone is a 7-form structure, as meantone is most usefully conceptualized as containing 7 interval categories and can be reasonably simplified to 7edo to understand its structure. Superpyth is a 5-form structure, and shares this property with many other temperaments in 2.3.7.