Minor Sixth

A minor sixth spans six letter names and eight half steps: E up to C, A up to F, B up to G, C up to A♭. Abbreviated m6, it measures 800 cents in equal temperament.

▶E–C0:06▶A–F0:06▶C–A♭0:07

Counting it

E–F–G–A–B–C is six letters, so E–C is a 6th. Counting eight keys one by one is slow, so most musicians use a shortcut: a 6th is an octave minus a 3rd. E up to the next E is 12 half steps, and C lies a major third (4 half steps) below that upper E. So E–C is 12 − 4 = 8 half steps, a minor sixth.

Among the white keys, three 6ths are minor: E–C, A–F and B–G. The other four (C–A, D–B, F–D, G–E) are major. Lower the top note of a major sixth by a half step and it becomes minor: C–A becomes C–A♭.

Where you hear it

The minor sixth is the inversion of the major third, so it appears whenever a major chord has its third in the bass. In a first-inversion C major chord (E–G–C, see chord inversion), the outer notes E and C form a minor sixth. In minor keys, the 6th degree lies a minor sixth above the tonic (F above A in A minor), and its tendency to sink a half step to the 5th degree (F to E) is part of what gives minor-key music its sighing quality.

As a melodic leap, a rising minor sixth is wide and expressive. One way to find it: sing up a perfect fifth, then one half step more.

Consonance

In classical theory both sixths are imperfect consonances. A minor sixth sounds sweet, a little darker than a major sixth.

Inversion and look-alikes

Inverted, a minor sixth becomes a major third: E–C becomes C–E, and 8 + 4 = 12. The same keys spelled with five letter names, such as C–G♯, form an augmented fifth, the outer interval of an augmented triad.

Practice with The 6th, the 7th & the Octave and Invert the intervals.