The musical interval of a perfect fifth is the relationship between the first note (the root or tonic) and the fifth note in a major scale. It is the inversion of the perfect fourth. Its abbreviation is P5.

It can be produced by starting on a high note and playing the fifth below or by starting on a low note and playing the fifth above.

A perfect fifth in just intonation most often corresponds to a pitch ratio of 2:3 or 1:1.5, or various other ratios, while in an equal tempered tuning, a perfect fifth is equal to seven (7) semitones, a ratio of 1:2^7/12 (approximately 1.4983), or 700 cents,two cents smaller.

The circle of fifths is a model of pitch space for the chromatic scale (chromatic circle) which considerness nearness not as adjacency but as perfect fifths.

The perfect fifth is considered the most consonant interval outside of the unison and octave.

The strings on violins, violas, and cellos are all tuned to perfect fifths unless in scordatura.

See also

• musical tuning
• diapente
• diminished fifth

External links

• Tonalsoft Encyclopaedia of Tuning