Subminor and supermajor

Traditionally, "supermajor and superminor, [are] the names given to certain thirds [9:7 and 17:14] found in the justly intoned scale with a natural or subminor seventh.

Thus, a subminor second is intermediate between a minor second and a diminished second (enharmonic to unison).

An example of such an interval is the ratio 7:6 (E♭), or 266.87 cents,[3][4] the septimal minor third, the inverse of the supermajor sixth.

An example of such an interval is the ratio 9:7, or 435.08 cents, the septimal major third (E).

An example of such an interval is the ratio 8:7, or 231.17 cents,[1] also known as the septimal whole tone (D- Playⓘ) and the inverse of the subminor seventh.

Composer Lou Harrison was fascinated with the 7:6 subminor third and 8:7 supermajor second, using them in pieces such as Concerto for Piano with Javanese Gamelan, Cinna for tack-piano, and Strict Songs (for voices and orchestra).

[13] 19 equal temperament has several intervals which are simultaneously subminor, supermajor, augmented, and diminished, due to tempering and enharmonic equivalence (both of which work differently in 19-ET than standard tuning).