Acoustic Science & Musical Pitch
Piano Keys & Note Frequencies Chart
From deep 27.5 Hz A0 bass rumbles to 4,186 Hz C8 bell chimes. Explore Middle C (C4), standard 440 Hz orchestra tuning, and the physics of 88 keys.
Select A Piano Landmark Key (Bass to Treble):
Scientific Pitch & Acoustics
Middle C (C4)
🎵 Frequency: 261.63 Hz
Octave Register:
Octave 4
Acoustic & Musical Function:
Key #40. The universal anchor note. Divides the treble clef (right hand) and bass clef (left hand).
Standard 88-Key Piano Architecture
88 Keys Total
52 White Natural Keys (A, B, C, D, E, F, G) + 36 Black Accidental Keys (Sharps # / Flats ♭).
440 Hz Standard (A440)
Standardized by ISO 16 in 1955. Debunks the internet myth of "432 Hz healing vibrations".
Equal Temperament (12-TET)
The octave is divided into 12 mathematically equal semitones (frequency multiplies by 2^(1/12) ≈ 1.059463 each half-step).