Minor seventh

minor seventh

Inverse	major second
Name
Other names	-
Abbreviation	m7
Size
Semitones	10
Interval class	2
Just interval	16:9[1] or 9:5[2]
Cents
Equal temperament	1000
24 equal temperament	1000
Just intonation	996.09 or 1017.596

Minor seventh  Play (help·info) equal tempered or  just (help·info).

Lesser just/Pythagorean small minor seventh  Play (help·info), two inverted perfect fifths.

Harmonic seventh  Play (help·info), septimal seventh.

In classical music from Western culture, a seventh is a musical interval encompassing seven staff positions (see Interval (music)#Number for more details), and the minor seventh is one of two commonly occurring sevenths. The minor quality specification identifies it as being the smallest of the two: the minor seventh spans ten semitones, the major seventh eleven. For example, the interval from A to G is a minor seventh, as the note G lies ten semitones above A, and there are seven staff positions from A to G. Diminished and augmented sevenths span the same number of staff positions, but consist of a different number of semitones (nine and twelve).

Minor seventh intervals are featured in melodies less often than the rarely featured major sevenths, at least the openings, with the best-known exception being the first two notes of the main theme from Star Trek: The Original Series theme.^[3] Other examples include the first two words of the phrase "There's a place us" from the song "Somewhere" in West Side Story.^[4]

The most common occurrence of the minor seventh is built on the root of the prevailing key's dominant triad, producing the all-important dominant seventh chord.

Harry Partch distinguishes between the 16:9 "small just 'minor seventh'" and the 9:5 "large just 'minor seventh'".^[5] A minor seventh in just intonation, also known as Pythagorean small minor seventh, typically corresponds to a pitch ratio of 16:9^[6] (Pythagorean small minor seventh  Play (help·info)) or 9:5  Play (help·info)^[7] (5-limit large minor seventh), while in an equal tempered tuning it is a ratio of 2^5/6:1 (about 1.782), or 1000 cents, 3.91 cents wider than the 16:9 ratio and 17.60 cents narrower than the 9:5 ratio.

An interval close in frequency is the harmonic seventh, or septimal minor seventh,^[8] with an exact 7:4 ratio (i.e., 1.75), which makes it quasi-harmonically significant. This interval is about 969 cents, or one-third of a semitone flatter than the equal-temperament minor seventh (1000 cents).

Consonance and dissonance are relative, depending on context, the minor seventh being defined as a dissonance requiring resolution to a consonance^[9]

See also

• Minor seventh chord
• Musical tuning
• List of meantone intervals

Sources

1. ^ Haluska (2003), p.xxiv. Pythagorean minor seventh.
2. ^ Haluska, Jan (2003). The Mathematical Theory of Tone Systems, p.xxiii. ISBN 0824747143. Just minor seventh.
3. ^ Keith Wyatt, Carl Schroeder, Joe Elliott (2005). Ear Training for the Contemporary Musician, p.69. ISBN 0793581931.
4. ^ Neely, Blake (2009). Piano For Dummies, p.201. ISBN 0470496444.
5. ^ Partch, Harry (1979). Genesis of a Music, p.68. ISBN 030680106X.
6. ^ "On Certain Novel Aspects of Harmony", p.119. Eustace J. Breakspeare. Proceedings of the Musical Association, 13th Sess., (1886 - 1887), pp. 113-131. Published by: Oxford University Press on behalf of the Royal Musical Association.
7. ^ "The Heritage of Greece in Music", p.89. Wilfrid Perrett. Proceedings of the Musical Association, 58th Sess., (1931 - 1932), pp. 85-103. Published by: Oxford University Press on behalf of the Royal Musical Association.
8. ^ David Dunn, 2000. Harry Partch: an anthology of critical perspectives.
9. ^ Benward & Saker (2003). Music: In Theory and Practice, Vol. I, p.53. Seventh Edition. ISBN 978-0-07-294262-0.