Chapter 2
Nine semitones span the notes of a major sixth interval.
The interval of the major sixth spans two harmonic multipliers.
This interval covers six white positions of the major scale. Nine semitones span the notes of a major sixth interval.
The interval between the fifth harmonic (5X) and the third harmonic (3X) gives the major sixth interval.
The frequency ratio of the major sixth is 5X/3X = 5:3.
For the Major C scale, the major sixth interval above the tonic gives the A note position.
For major keys, a note at the major sixth interval above the Tonic is known as the relative minor position. Relative minor scales, keys, and chords are important in music and are covered extensively in a separate course.
The chord at the sixth position progresses most harmoniously to the perfect fourth and forms part of chord progressions for a disproportionally large number of classic hits.
Nine semitones span the notes of a major sixth interval.