A0
Frequency, piano key and harmonics
A0 is the lowest key on an 88-key piano. A 4-string bass cannot reach it. A 5-string bass in standard tuning bottoms at B0, a whole step higher.
| Harmonic | Frequency | Nearest equal-tempered note |
|---|---|---|
| 1 · fundamental | 27.50 Hz | A0 (+0 ¢) |
| 2× | 55.00 Hz | A1 (+0 ¢) |
| 3× | 82.50 Hz | E2 (+2 ¢) |
| 4× | 110.00 Hz | A2 (+0 ¢) |
| 5× | 137.50 Hz | C♯3 (−14 ¢) |
| 6× | 165.00 Hz | E3 (+2 ¢) |
Piano playback uses the nearest piano sample, played faster or slower, plus a sine wave at the exact pitch. The sine button is the exact equal-tempered frequency. Neighbors: C8 and A♯0. Arbitrary pitches and alternate A4 tunings belong on the calculator.
Hear the note. Then name the interval.
Interval and chord drills in the app are built on this same piano and this same tuning.
Download on theApp Store- EQ & compressionDaily drills on drums, bass, guitars and full mixes.
- Intervals & chordsPiano training that uses the same note names as these pages.
- Studio toolsMetronome, tone generator and tap tempo live in the app too.
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FAQ
A0 questions
What frequency is A0?
27.50 Hz when A4 is 440 Hz. Change the reference on the note calculator if you need another tuning. This page does not change.
What MIDI note is A0?
MIDI 21. Piano key 1, counting A0 as key 1 and C8 as key 88.
How loud should I listen?
Keep the tone at a conversation level. These pages can generate steady tones and noise, which fatigue your ears faster than music. If anything rings or feels uncomfortable, stop and turn the volume down.