What is a fifth?

A fifth is a musical interval encompassing five staff positions, and the specific quality of the fifth (perfect, augmented, or diminished) depends on the number of half steps it contains.

  • The most common type is the perfect fifth, spanning seven semitones. It is considered a very consonant interval and is a fundamental building block of harmony. Perfect fifths are found in major and minor scales.

  • An augmented fifth is a fifth that is a semitone larger than a perfect fifth, spanning eight semitones.

  • A diminished fifth is a fifth that is a semitone smaller than a perfect fifth, spanning six semitones. The diminished fifth, also known as a tritone, is dissonant.