In music theory, a doubly diminished fifth is an interval that has five half steps 
The doubly diminished fifth requires that:
- The interval must be a fifth interval (five note names between the first and the last).
- The interval must have five half steps.
What does a doubly diminished fifth look like?
Here is an example of a melodic doubly diminished fifth (two music notes in a melody) and a harmonic doubly diminished fifth (in a chord):
How to recognize a doubly diminished fifth?
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 F♯ / C♭:
Let's take the F major scale to have F as the tonic:
From the rule stated above, the interval F♮ / C♮ is a perfect fifth, so the interval F♯ / C♮ is a diminished fifth, and so the interval F♯ / C♭ is a doubly diminished fifth.
Inversion of the doubly diminished fifth
The inversion of the doubly diminished fifth is the doubly augmented fourth.
Here is an example of a doubly augmented fourth:
Musical examples of doubly diminished fifth
No examples yet, but feel free to send me some examples!
Interval identification game
You will find this interval in my Intervals identification game:
