Piano note
C♯4 / D♭4 Piano Note Frequency
C♯4 / D♭4 is key 41 of the 88 on a standard piano, with a frequency of 277.18 Hz when the piano is tuned to A4 = 440 Hz.
277.18 Hz
C♯4 / D♭4 at a glance
- Frequency (A4 = 440 Hz)
- 277.18 Hz
- At A4 = 442 Hz
- 278.44 Hz
- At A4 = 432 Hz
- 272.14 Hz
- Piano key number
- 41 / 88
- MIDI note number
- 61
- Octave
- 4
- Key colour
- Black key
- Wavelength in air
- 1.24 m
- Period (one vibration)
- 3.61 ms
- Register
- Middle
Wavelength assumes sound travels at 343 m/s (air at about 20 °C).
About this part of the keyboard
This black key has two names: C♯4 and D♭4. They are the same key and the same frequency on a piano.
This is the heart of the keyboard around middle C. On most pianos each note here has three plain steel strings (a trichord) that must match each other exactly. Tuners usually start here, setting the temperament octave and A4 before tuning the rest of the piano from it.
Neighbouring keys
Is your C♯4 in tune?
Play C♯4 on your piano and our free online tuner will show how many cents it is from 277.18 Hz.
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