2020/11/23 · perfect fifth ( plural perfect fifths ) ( music) an interval equal to that of between the second and third harmonics of the harmonic series; in equal temperament, an interval of seven semitones spanning five degrees of the diatonic scale. It is enharmonically equivalent to a diminished sixth . The perfect fifth has a pitch ratio close to 3:2.

Moved Permanently. The document has moved here.

• An approximation: new standard tuning ·
• Relation with all-fourths tuning ·
• Notes

This interval is called a "fifth" if it occurs between the first note and the fifth note on the scale (or more generally between two notes with three notes in between). The perfect fifth differs from the augmented fifth (eight semitones instead of seven) or the diminished fifth (six semitones), which are intervals that are less common.

• Definition ·
• Structure and use ·
• History ·
• Use ·
• Related concepts ·
• See also

完全五度（かんぜんごど）とは、音楽における音程のひとつである。 P5 (Perfect 5th) と略記する。純正律においては、根音と完全五度の振動数の比が2:3になる。 完全四度の 転回形 （英語 …

The perfect fifth is represented almost completely accurately in 12-tone equal temperament, suggesting that its accuracy is fundamental to music. The Root Note of the Nearest Key In any given key, the closest tonality The key in which a piece is played, and the relationships of the notes to each other, and most especially to the tonal center. is the key of the 5 th or 4 th degrees.