C is a white key on the piano. It sounds at 261.63 Hz in octave 4.
C can also be written as His. These are enharmonic equivalents: the same pitch, the same key on the piano, a different name on the page. Which spelling is correct depends on the key and on how the note functions, not on the sound.
Frequencies for C in scientific pitch notation, with A4 tuned to 440 Hz.
| Note | MIDI | Frequency |
|---|---|---|
| C1 | 24 | 32.7 Hz |
| C2 | 36 | 65.41 Hz |
| C3 | 48 | 130.81 Hz |
| C4 | 60 | 261.63 Hz |
| C5 | 72 | 523.25 Hz |
| C6 | 84 | 1046.5 Hz |
| C7 | 96 | 2093 Hz |
The most common chords built with C as the root.
Keys and scales that use C as their tonic.
C is a white key on the piano.
C4 sounds at 261.63 Hz with A4 tuned to 440 Hz.
C can also be written as His. They are the same pitch spelled differently.