Frequency Atlas
Musical Frequencies

C8

4.2 kHz
Note: C8
Cosmic Octave Color
Derived visible color (521 nm)
Display swatch #44c55f
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 model

Musical note C in octave 8. High treble range.

Period
0.24 ms
Wavelength
8.2 cm
Nearest Note
C8 (0¢)
Claim Type
Musical Standard
Cosmic Octave Color
Derived visible color (521 nm) · #44c55f
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

musicequal-temperamentoctave-8