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Perfect fifth

What is perfect fifth? A clear definition from the acoustics and tuning & pitch section of our glossary, with 13 related terms, tools to try and further reading.

Definition of Perfect fifth

In Western music theory, a perfect fifth (abbreviated P5) is a musical interval corresponding to a pair of pitches with a frequency ratio of 3:2, or very nearly so.

A fifth is an interval spanning five staff positions. The diminished fifth and augmented fifth are one chromatic semitone narrower and wider than the perfect fifth respectively. The perfect fifth spans seven semitones in equal temperament. For example, the interval from C to G is a perfect fifth, as it spans five staff positions and G lies seven semitones above C.

The perfect fifth may be derived from the harmonic series as the interval between the second and third harmonics. In a diatonic scale, the dominant note is a perfect fifth above the tonic note.

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What is Perfect fifth?

In Western music theory, a perfect fifth (abbreviated P5) is a musical interval corresponding to a pair of pitches with a frequency ratio of 3:2, or very nearly so.

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