Reference

Fifths

Fifths can be perfect, augmented or diminished. Below you can see that the number of steps determines the quality of the interval:

Diminished fifth, 3 whole steps or 6 half steps

Perfect fifth, 3 1/2 whole steps or 7 half steps

Augmented fifth, 4 whole steps or 8 half steps

Identifying fifths

When analyzing the quality of a fifth we should know that:

• the interval is a perfect fifth if all the notes are natural, with the exception of the fifth B-F, which is a diminished fifth.

If there are accidentals you should identify the interval without accidentals and then analyze the effect of the accidentals.

 Example: D-A#:

Another example: Gb-Db:

Identifying fifths by counting whole and half steps is slow and confusing. See Simplifying accidentals.