Musical Frequencies
E4
329.63 Hz
Note: E4
Cosmic Octave Color
Derived visible color (414 nm)
Display swatch #7f52ef
EstablishedMusical Standard
Evidence Level
Established
Source Count
1
Last Reviewed
March 23, 2026
Directly measured, standardized, or well-supported in mainstream scientific or technical literature.
This entry documents a musical reference or standard. It should be read as an acoustic and musical reference rather than a biological claim.
Review the evidence modelMusical note E in octave 4. Mid to treble range.
Period
3.03 ms
Wavelength
1.04 m
Nearest Note
E4 (0¢)
Claim Type
Musical Standard
Cosmic Octave Color
Derived visible color (414 nm) · #7f52ef
Source
Equal temperament tuning system (A4 = 440 Hz)
Sources
Equal Temperament Tuning System
108 atlas references
The twelve-tone equal temperament reference used for note-frequency lookups throughout the atlas.
Standard equal-temperament note table with A4 = 440 Hz.
Harmonic Series
Octave Ladder
Every audible octave of this frequency — the same tone, higher and lower.
Nearby in the Atlas
Entries within ±35 cents of this tone when reduced to the same octave — candidates for pairing or comparison.
E5Musical Frequencies
659.26 Hz0¢
E6Musical Frequencies
1.3 kHz0¢
E7Musical Frequencies
2.6 kHz0¢
E8Musical Frequencies
5.3 kHz0¢
E2Musical Frequencies
82.41 Hz+0.1¢
E3Musical Frequencies
164.81 Hz-0.1¢
musicequal-temperamentoctave-4