G♯-1 / A♭-1
12.978Hz at concert pitch
Press to hear a pure sine tone at this pitch.
MIDI note
8
Piano key
—
Octave
-1
Frequency
12.978 Hz
Period
77.0535 ms
Wavelength
26.4293 m
Pitch class
G♯
Notation
SPN
MIDI is the note number synths and software pass around (0–127). Pitch class is the note without its octave — all the G♯s share one. Enharmonic spellings (G♯-1 and A♭-1) name the same pitch two ways. This note falls outside the 88-key piano, so it has no piano key number.
At other reference pitches
| Reference (A4) | G♯-1 frequency | Where you meet it |
|---|---|---|
| 432 Hz | 12.742 Hz | the alternative-tuning circle |
| 440 Hzstandard | 12.978 Hz | the ISO 16 standard — concert pitch |
| 442 Hz | 13.037 Hz | many European orchestras tune a touch sharp |
| 443 Hz | 13.067 Hz | some sharper continental orchestras |
Every row is G♯-1 — only the A4 you tune to changes. A frequency scales straight with the reference: G♯-1 at 432 Hz is the 440 Hz value times 432⁄440.
Move around
Every G♯
Chords with G♯ in them
G♯ appears in each of these — see the whole chord grid.