The major and minor sixth ratios derive by complementing thirds within an octave

Evidence

Two other common intervals are the major sixth and minor sixth, and their frequency ratios can be found from those for the minor third and major third, respectively, since in each case they combine to make one octave. — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 806

Categorization

• DEFINE: Continues the octave-complement method for deriving sixth intervals from thirds.
• XREF: connects to: Stacking perfect fifths yields the octave, fifth, and fourth intervals. — Eric J. Heller, Why You Hear What You Hear- An…, 2360; Musical intervals trace directly to harmonic-series frequency ratios — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 811

Broader Connections

• Musical intervals trace directly to harmonic-series frequency ratios #expands (0.80) — David M. Howard, Jamie Angus, Acoustics and Psychoacoustics, 811
• Stacking perfect fifths yields the octave, fifth, and fourth intervals. #expands (0.75) — Eric J. Heller, Why You Hear What You Hear- An…, 2360