C1 — 32.70 Hz
C1 (MIDI 24) vibrates 32.70 times per second at standard concert pitch. Play the reference tone below, or tune to it with the online tuner.
C1 at different reference pitches
| Reference (A4) | C1 frequency | Used for |
|---|---|---|
| 415 Hz | 30.85 Hz | Baroque pitch |
| 432 Hz | 32.11 Hz | “Verdi” pitch |
| 440 Hz | 32.70 Hz | Standard concert pitch |
| 442 Hz | 32.85 Hz | European orchestras |
| 444 Hz | 33.00 Hz | European orchestras |
Physical properties
- Period: one cycle every 30.58 ms
- Wavelength in air: ≈ 10.49 m (at 20 °C, 343 m/s)
- MIDI note number: 24
- Octave up: C2 = 65.41 Hz · Octave down: 16.35 Hz