In music, a subminor interval is an interval that is noticeably wider than a diminished interval but noticeably narrower than a minor interval. It is found in between a minor and diminished interval, thus making it below, or subminor to, the minor interval. A supermajor interval is a musical interval that is noticeably wider than a major interval but noticeably narrower than an augmented interval. It is found in between a major and augmented interval, thus making it above, or supermajor to, the major interval. The inversion of a supermajor interval is a subminor interval, and there are four major and four minor intervals, allowing for eight supermajor and subminor intervals, each with variants.
More information supermajor ...
diminished
subminor
minor
neutral
major
supermajor
augmented
seconds
D
≊ D
D♭
D
D
≊ D
D♯
thirds
E
≊ E
E♭
E
E
≊ E
E♯
sixths
A
≊ A
A♭
A
A
≊ A
A♯
sevenths
B
≊ B
B♭
B
B
≊ B
B♯
Close
Origin of large and small seconds and thirds (including 7:6) in harmonic series.[1]
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."[2]
Subminor second and supermajor 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 26:25, or 67.90 cents (D-Playⓘ). Another example is the ratio 28:27, or 62.96 cents (C♯-Playⓘ).
A supermajor seventh is an interval intermediate between a major seventh and an augmented seventh. It is the inverse of a subminor second. Examples of such an interval is the ratio 25:13, or 1132.10 cents (B♯); the ratio 27:14, or 1137.04 cents (BPlayⓘ); and 35:18, or 1151.23 cents (CPlayⓘ).
Subminor third on G Playⓘ and its inverse, the supermajor sixth on B♭Playⓘ
A subminor third is in between a minor third and a diminished third. 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. Another example is the ratio 13:11, or 289.21 cents (E↓♭).
A supermajor sixth is noticeably wider than a major sixth but noticeably narrower than an augmented sixth, and may be a just interval of 12:7 (A).[5][6][7] In 24 equal temperament A = B. The septimal major sixth is an interval of 12:7 ratio (APlayⓘ),[8][9] or about 933 cents.[10] It is the inversion of the 7:6 subminor third.
A subminor sixth or septimal sixth is noticeably narrower than a minor sixth but noticeably wider than a diminished sixth, enharmonically equivalent to the major fifth. The sub-minor sixth is an interval of a 14:9 ratio[6][7] (A♭) or alternately 11:7.[5] (G↑-Playⓘ) The 21st subharmonic (see subharmonic) is 729.22 cents. Playⓘ
A supermajor third is in between a major third and an augmented third, enharmonically equivalent to the minor fourth. An example of such an interval is the ratio 9:7, or 435.08 cents, the septimal major third (E). Another example is the ratio 50:39, or 430.14 cents (E♯).
A supermajor second (or supersecond[2]) is intermediate to a major second and an augmented second. 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. Another example is the ratio 15:13, or 247.74 cents (D♯).
Use
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).[12] Together the two produce the 4:3 just perfect fourth.[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). For example, four steps of 19-ET (an interval of roughly 253 cents) is all of the following: subminor third, supermajor second, augmented second, and diminished third.
Miller & Lieberman (2006), p. 74. "The subminor third and supermajor second combine to create a pure fourth (8⁄7 x 7⁄6 = 4⁄3)."[incomplete short citation]
