|Other names||septimal major sixth, supermajor sixth, major hexachord, greater hexachord, hexachordon maius|
|Just interval||5:3 or 12:7|
|24 equal temperament||900|
|Just intonation||884 or 933|
In classical music from Western culture, a sixth is a musical interval encompassing six staff positions (see Interval number for more details), and the major sixth is one of two commonly occurring sixths. It is qualified as major because it is the larger of the two. The major sixth spans nine semitones, its smaller counterpart being the minor sixth, spanning eight semitones. For example, the interval from C to A is a major sixth, as the note A lies nine semitones above C, and there are six staff positions from C to A. Diminished and augmented sixths span the same number of staff positions, but consist of a different number of semitones (seven and ten).
The major sixth is one of consonances of common practice music, along with the unison, octave, perfect fifth, major and minor thirds, minor 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[vague] they were tuned to the Pythagorean major sixth of 27/16. In just intonation, the major sixth is classed as a consonance of the 5-limit. A major sixth is also used in transposing music to E-flat instruments, like the alto clarinet, alto saxophone, E-flat tuba, trumpet and horn (instrument) when in E-flat as a written C sounds like E-flat on those instruments.
The major sixth occurs in first inversion minor chords, second inversion major chords, and either version of a diminished chord. It occurs in the second and third inversions of a dominant seventh chord. The septimal major sixth is approximated in 53 tone equal temperament by an interval of 41 steps or 928 cents.
The file plays middle C, followed by A (a tone 900 cents sharper than C), followed by both tones together.
|Problems listening to this file? See media help.|
Frequency proportions 
A major sixth in just intonation most often corresponds to a pitch ratio of 5:3 ( play (help·info)), or 884 cents, while in 12-tone equal temperament, a major sixth is equal to nine semitones, or 900 cents, 15.641 cents higher than the just major sixth and 33 cents lower than the 12:7 septimal major sixth or supermajor sixth of 933 cents.
The Pythagorean major sixth, or 27th harmonic, is 27:16 or 906 cents, constructed from three just perfect fifths (C-A = C-G-D-A = 702+702+702=2106-1200=906). The 27:16 Pythagorean major sixth arises in the C major scale between F and D. Play (help·info)
Further reading 
- Duckworth, William (2009). Sound and Light: La Monte Young, Marian Zazeela, p. 167. ISBN 0-8387-5738-3. [septimal]
See also 
- Haluska, Jan (2003). The Mathematical Theory of Tone Systems, p.xxiii. ISBN 0-8247-4714-3. Septimal major sixth.
- Neely, Blake (2009). Piano For Dummies, p.201. ISBN 0-470-49644-4.
- Hermann L. F Von Helmholtz (2007). On the Sensations of Tone, p.456. ISBN 1-60206-639-6.
- John Fonville. "Ben Johnston's Extended Just Intonation- A Guide for Interpreters", p.124, Perspectives of New Music, Vol. 29, No. 2 (Summer, 1991), pp. 106-137.
- Paul, Oscar (1885). A manual of harmony for use in music-schools and seminaries and for self-instruction, p.165. Theodore Baker, trans. G. Schirmer.