A#4 — 466.16 Hz
A#4 (MIDI 70) vibrates 466.16 times per second at standard concert pitch. Play the reference tone below, or tune to it with the online tuner.
A#4 at different reference pitches
| Reference (A4) | A#4 frequency | Used for |
|---|---|---|
| 415 Hz | 439.68 Hz | Baroque pitch |
| 432 Hz | 457.69 Hz | “Verdi” pitch |
| 440 Hz | 466.16 Hz | Standard concert pitch |
| 442 Hz | 468.28 Hz | European orchestras |
| 444 Hz | 470.40 Hz | European orchestras |
Physical properties
- Period: one cycle every 2.15 ms
- Wavelength in air: ≈ 73.6 cm (at 20 °C, 343 m/s)
- MIDI note number: 70
- Octave up: A#5 = 932.33 Hz · Octave down: 233.08 Hz