|Other names||minor hexachord, hexachordon minus, lesser hexachord|
|Just interval||8:5, 11:7, 128:81|
|24 equal temperament||800|
|Just intonation||814, 782, 792|
In classical music from Western culture, a sixth is a musical interval encompassing six staff positions (see Interval number for more details), and the minor sixth is one of two commonly occurring sixths. It is qualified as minor because it is the smaller of the two: the minor sixth spans eight semitones, the major sixth nine. For example, the interval from A to F is a minor sixth, as the note F lies eight semitones above A, and there are six staff positions from A to F. Diminished and augmented sixths span the same number of staff positions, but consist of a different number of semitones (seven and ten).
A minor sixth in just intonation most often corresponds to a pitch ratio of 8:5 or 1.6:1 (play (help·info)) of 814 cents; in 12-tone equal temperament, a minor sixth is equal to eight semitones, a ratio of 22/3:1 (about 1.587), or 800 cents, 13.7 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 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 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).
|Just interval||14:9 or 63:40|
|24 equal temperament||750|
|Just intonation||765 or 786|