Perfect Fifth

In classical music from Western culture, a fifth is a musical interval encompassing five staff positions (see Interval number for more details), and the perfect fifth (often abbreviated P5) is a fifth spanning seven semitones, or in meantone, four diatonic semitones and three chromatic semitones. For example, the interval from C to G is a perfect fifth, as the note G lies seven semitones above C, and there are five staff positions from C to G. Diminished and augmented fifths span the same number of staff positions, but consist of a different number of semitones (six and eight, respectively).

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.

The perfect fifth is more consonant, or stable, than any other interval except the unison and the octave. It occurs above the root of all major and minor chords (triads) and their extensions. Until the late 19th century, it was often referred to by one of its Greek names, diapente. Its inversion is the perfect fourth.

Read more about Perfect Fifth:  Alternative Definitions, Other Qualities of Fifth, The Pitch Ratio of A Fifth, Use in Harmony, Bare Fifth, Open Fifth, or Empty Fifth, Use in Tuning and Tonal Systems

Famous quotes containing the word perfect:

    We are compelled by the theory of God’s already achieved perfection to make Him a devil as well as a god, because of the existence of evil. The god of love, if omnipotent and omniscient, must be the god of cancer and epilepsy as well.... Whoever admits that anything living is evil must either believe that God is malignantly capable of creating evil, or else believe that God has made many mistakes in His attempts to make a perfect being.
    George Bernard Shaw (1856–1950)