Musical Frequencies
A2
110.00 Hz
Note: A2
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 2. Bass to mid range.
Period
9.09 ms
Wavelength
3.12 m
Nearest Note
A2 (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
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.
A0Musical Frequencies
27.50 Hz0¢
A1Musical Frequencies
55.00 Hz0¢
A3Musical Frequencies
220.00 Hz0¢
A4Musical Frequencies
440.00 Hz0¢
A5Musical Frequencies
880.00 Hz0¢
A6Musical Frequencies
1.8 kHz0¢
musicequal-temperamentoctave-2