F♯-1 / G♭-1
11.562Hz at concert pitch
Press to hear a pure sine tone at this pitch.
MIDI note
6
Piano key
—
Octave
-1
Frequency
11.562 Hz
Period
86.4902 ms
Wavelength
29.6661 m
Pitch class
F♯
Notation
SPN
MIDI is the note number synths and software pass around (0–127). Pitch class is the note without its octave — all the F♯s share one. Enharmonic spellings (F♯-1 and G♭-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) | F♯-1 frequency | Where you meet it |
|---|---|---|
| 432 Hz | 11.352 Hz | the alternative-tuning circle |
| 440 Hzstandard | 11.562 Hz | the ISO 16 standard — concert pitch |
| 442 Hz | 11.615 Hz | many European orchestras tune a touch sharp |
| 443 Hz | 11.641 Hz | some sharper continental orchestras |
Every row is F♯-1 — only the A4 you tune to changes. A frequency scales straight with the reference: F♯-1 at 432 Hz is the 440 Hz value times 432⁄440.
Move around
Every F♯
Chords with F♯ in them
F♯ appears in each of these — see the whole chord grid.