A2 — 110.00 Hz
A2 (MIDI 45) vibrates 110.00 times per second at standard concert pitch. Play the reference tone below, or tune to it with the online tuner.
A2 at different reference pitches
| Reference (A4) | A2 frequency | Used for |
|---|---|---|
| 415 Hz | 103.75 Hz | Baroque pitch |
| 432 Hz | 108.00 Hz | “Verdi” pitch |
| 440 Hz | 110.00 Hz | Standard concert pitch |
| 442 Hz | 110.50 Hz | European orchestras |
| 444 Hz | 111.00 Hz | European orchestras |
Physical properties
- Period: one cycle every 9.09 ms
- Wavelength in air: ≈ 3.12 m (at 20 °C, 343 m/s)
- MIDI note number: 45
- Octave up: A3 = 220.00 Hz · Octave down: 55.00 Hz
Strings tuned to A2
- Guitar — Standard (E A D G B E)
- Guitar — Drop D (D A D G B E)
- Guitar — Open A (E A E A C# E)
- Guitar — Open D (D A D F# A D)
- Guitar — DADGAD
- Guitar — Drop A (A E A D F# B)
- Guitar — Double Drop D (D A D G B D)
- Guitar — All Fourths (E A D G C F)
- 7-String Guitar — Standard (B E A D G B E)
- 7-String Guitar — Drop A (A E A D G B E)
- 8-String Guitar — Standard (F# B E A D G B E)
- 8-String Guitar — Drop E (E B E A D G B E)
- 12-String Guitar — Standard (E A D G B E, octave courses)