# Doubly diminished fourth

In music theory, a doubly diminished fourth is an interval that has three half steps (semitones ).

The doubly diminished fourth requires that:

- The interval must be a fourth interval (four note names between the first and the last).

- The interval must have three half steps.

## What does a doubly diminished fourth look like?

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

## How to recognize a doubly diminished fourth?

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 C / F♭♭:

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

From the rule stated above, the interval C / F is a perfect fourth, so the interval C / F♭ is a diminished fourth, and so the interval C / F♭♭ is a doubly diminished fourth.

## Inversion of the doubly diminished fourth

The inversion of the doubly diminished fourth is the doubly augmented fifth.

Here is an example of a doubly augmented fifth:

## Musical examples of doubly diminished fourth

No examples yet, but feel free to send me some examples!

## Interval identification game

You will find this interval in my Intervals identification game: