What is "major sixth"

Major \Ma"jor\, [L. major, compar. of magnus great: cf. F. majeur. Cf. Master, Mayor, Magnitude, More, a.]

1. Greater in number, quantity, or extent; as, the major part of the assembly; the major part of the revenue; the major part of the territory.

2. Of greater dignity; more important.
   --Shak.

3. Of full legal age; adult. [Obs.]

4. (Mus.) Greater by a semitone, either in interval or in difference of pitch from another tone.

   Major key (Mus.), a key in which one and two, two and three, four and five, five and six and seven, make major seconds, and three and four, and seven and eight, make minor seconds.

   Major offense (Law), an offense of a greater degree which contains a lesser offense, as murder and robbery include assault.

   Major scale (Mus.), the natural diatonic scale, which has semitones between the third and fourth, and seventh and fourth, and seventh and eighth degrees; the scale of the major mode, of which the third is major. See Scale, and Diatonic.

   Major second (Mus.), a second between whose tones is a difference in pitch of a step.

   Major sixth (Mus.), a sixth of four steps and a half step. In major keys the third and sixth from the key tone are major. Major keys and intervals, as distinguished from minors, are more cheerful.

   Major third (Mus.), a third of two steps.

n. (context music English) A musical interval of the Western twelve-semitone system consisting of nine semitone and spanning six degrees of the diatonic scale. It is one semitone wider than a minor sixth and enharmonically equivalent to a diminished seventh.

In music from Western culture, a sixth is a musical interval encompassing six note letter names or 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, the minor sixth, spans eight semitones. For example, the interval from C up to the nearest A is a major sixth. It's a sixth because it encompasses six note letter names (C, D, E, F, G, A) and six staff positions. It's a major sixth, not a minor sixth, because the note A lies nine semitones above C. Diminished and augmented sixths (such as C to A and C to A) span the same number of note letter names and staff positions, but consist of a different number of semitones (seven and ten).

A commonly cited example of a melody featuring the major sixth as its opening is " My Bonnie Lies Over the Ocean".

The major sixth is one of the 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 they were tuned to the Pythagorean major sixth of 27/16. In just intonation, the (5/3) 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, natural horn, and alto horn when in E-flat as a written C sounds like E-flat on those instruments.

Assuming close-position voicings for the following examples, the major sixth occurs in a first inversion minor triad, a second inversion major triad, and either inversion of a diminished triad. It also occurs in the second and third inversions of a dominant seventh chord.

The septimal major sixth (12/7) is approximated in 53 tone equal temperament by an interval of 41 steps or 928 cents.