Perfect 5th

7 semitones — the foundation of musical movement

Degree 5Solfège: soNotation: P5

The perfect 5th is an interval of 7 semitones — the most consonant interval after the octave, appearing on the 3rd harmonic (3:2). It is the beginning of musical movement via the circle of 5ths, and the backbone of the most important triads, tetrads, pentatonics, and every popular mode.

357912151719215C5CC5C5C55C5CC5C55C5C
The instrumentTap a note to hear it.
The perfect 5th in the harmonic series
f2f2f completes 2 cycles in one period of the sum2 cycles3f3f completes 3 cycles in one period of the sum3 cycles4f5f6f7f8f9f10f11f12f13f14f15f16fsum3:2 — the higher note vibrates 3 times for every 2 of the lower: harmonics 3 and 2 of one fundamental3:25: the perfect 5th — the interval's degree above the root, as the app writes it5The sum repeats every 2 cycles of 2f — the shorter this is, the more simply the two notes fit together, and the more consonant the intervalrepeats every 2 cycles16 cycles of 2f
Harmonic seriesEach row is one harmonic of the note — n times the fundamental's frequency, about 1/n of its strength — faster and fainter as it climbs. The rows in ink are where the chosen interval first arises. The bottom row is the one your ear actually receives: those rows added, a single wave. The shaded band is one repeat of it — the shorter that pattern, the sooner the ear settles on it as one sound. Harmonics 2 and 3 — the ratio 3:2: a perfect 5th. Together they repeat every 2 cycles of the lower note — the shorter that pattern, the sooner your ear has heard it come round enough times to settle on one sound. Equal temperament tunes it 2¢ narrower.

Related

Contained byIntervalsRelatedSolfègeRoot & 5thCircle of FifthsConsonanceDerived fromHarmonic SeriesReferenced byNestingShell VoicingsOctavePerfect 4th

Practiced in

5th Bounce