Musical Frequencies
A1
55.00 Hz
Note: A1
Cosmic Octave Color
Derived visible color (620 nm)
Display swatch #e9852d
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 A in octave 1. Sub-bass range.
Period
18.18 ms
Wavelength
6.24 m
Nearest Note
A1 (0¢)
Claim Type
Musical Standard
Cosmic Octave Color
Derived visible color (620 nm) · #e9852d
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-1