Music theory games > Lessons > Pitch of sounds > Intervals > Diminished sixth

Diminished sixth

In music theory, a diminished sixth is an interval that has seven half steps (semitones ).

The diminished sixth requires that:

- The interval must be a sixth interval (six note names between the first and the last).
- The interval must have seven half steps.

What does a diminished sixth look like?

Here is an example of a melodic diminished sixth (two music notes in a melody) and a harmonic diminished sixth (in a chord):

How to recognize a diminished sixth?

Rule of music theory: All intervals in a major scale starting with the tonic (degree I) are either major or perfect, and only unison, octave, fourth and fifth are perfect (the others are major).

Example with the interval G / E♭♭:

Let's take the G major scale to have G as the tonic:

From the rule stated above, the interval G / E♮ is a major sixth, so the interval G / E♭ is a minor sixth, and so the interval G / E♭♭ is a diminished sixth.