fifth

music

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June 26, 2026

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In music, a "fifth" is a fundamental interval that spans five diatonic degrees. It is one of the four perfect intervals, alongside the unison, octave, and fourth, which are based on simple numerical ratios and are perceived as consonant. The fifth is crucial in Western harmony, forming a cornerstone of its structure.1

Historically, the interval of a fifth was considered consonant and was used extensively in early forms of harmony like organum. The concept of the fifth is also central to the circle of fifths, a visual tool that illustrates the relationships between keys and key signatures in Western music. In modern tuning systems like equal temperament, the perfect fifth is slightly narrower than its acoustically pure form but remains a nearly imperceptible difference.234

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East Asian arts
Theoretical systems
This cycle of fifths produced 12 pitches that were mathematically correct, but the 13th pitch did not match the 1st pitch. In the West this so-called “Pythagorean comma” became bothersome as Western music oriented toward vertical sounds called harmony in which the distance between pitches in chords needed…
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This cycle of fifths produced 12 pitches that were mathematically correct, but the 13th pitch did not match the 1st pitch. In the West this so-called “Pythagorean comma” became bothersome as Western music oriented toward vertical sounds called harmony in which the distance between pitches in chords needed…
Read More

keyboard instrument
Organ stops
…mixtures these sound at a fifth above the unison (e.g., G above C), although ranks sounding at a third above and even at a flat seventh (e.g., E and B♭ above C) and their respective octaves are also found; but these are best restricted to mixtures intended for somewhat special…
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…mixtures these sound at a fifth above the unison (e.g., G above C), although ranks sounding at a third above and even at a flat seventh (e.g., E and B♭ above C) and their respective octaves are also found; but these are best restricted to mixtures intended for somewhat special…
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harmony
…harmony, are the octave, the fifth, and the fourth. (An octave, as from C to the C above it, encompasses eight white notes on a piano keyboard, or a comparable mixture of white and black notes. A fifth, as from C to G, encompasses five white notes; a fourth, as…
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…harmony, are the octave, the fifth, and the fourth. (An octave, as from C to the C above it, encompasses eight white notes on a piano keyboard, or a comparable mixture of white and black notes. A fifth, as from C to G, encompasses five white notes; a fourth, as…
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