Minor sixth

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minor sixth
Inverse major third
Name
Other names subminor sixth
Abbreviation m6
Size
Semitones 8
Interval class 4
Just interval 8:5, 14:9, 27:32
Cents
Equal temperament 800
24 tone equal temperament 750
Just intonation 814, 764.9, 906
Minor sixth About this sound Play

A minor sixth is the smaller of two commonly occurring musical intervals that span six diatonic scale degrees. The prefix 'minor' identifies it as being the smaller of the two (by a chromatic semitone); its larger counterpart being a major sixth. The minor 6th is abbreviated as m6, its inversion is the major third and in equal temperament is enharmonically equivalent to the augmented fifth. Its most common occurrence is between the third and (upper) root of major chords.

A minor sixth in just intonation most often corresponds to a pitch ratio of 8:5 or 1:1.6 (About this sound play ), or various other ratios including the 27:32 subminor sixth[1] (possibly 63:40[2]) of 906 cents (the Pythagorean major sixth), and the 14:9 septimal minor sixth[3] of 764.9 cents[4], while in an equal tempered tuning, a minor sixth is equal to eight semitones, a ratio of 22/3:1 (about 1.587), or 800 cents, 13.69 cents smaller. The ratios of both major and minor sixths are corresponding numbers of the Fibonacci sequence, 5 and 8 for a minor sixth and 3 and 5 for a major. The 11:7 undecimal minor sixth is 782.492 cents (About this sound Play ).

The minor sixth is one of consonances of common practice music, along with the unison, octave, perfect fifth, major and minor thirds, major sixth and (sometimes) the perfect fourth. In the common practice period, sixths were considered interesting and dynamic consonances along with their inverses the thirds, but in medieval times they were considered dissonances unusable in a stable final sonority; however it should be noted that in that period they were tuned very flat, to the Pythagorean minor sixth of 128/81. In just intonation, the minor sixth is classed as a consonance of the 5-limit.

Any note will only appear in major scales from any of its minor sixth major scale notes (for example, C is the minor sixth note from E and E will only appear in C, D, E, F, G, A and B major scales).

[edit] See also

[edit] Sources

  1. ^ Johannes Kepler (2009). The Harmonies of the World, p.107. ISBN 0559127936.
  2. ^ Hewitt, Michael (2000). The tonal phoenix, p.137. ISBN 3922626963.
  3. ^ Jan Haluska (2003). The Mathematical Theory of Tone Systems, p.xxiii. ISBN 0824747143.
  4. ^ Duckworth & Fleming (1996). Sound and Light: La Monte Young & Marian Zazeela, p.167. ISBN 0838753469.