D♯4 / E♭4
311.127Hz at concert pitch
Press to hear a pure sine tone at this pitch.
MIDI note
63
Piano key
43
Octave
4
Frequency
311.127 Hz
Period
3.2141 ms
Wavelength
1.1024 m
Pitch class
D♯
Notation
SPN
MIDI is the note number synths and software pass around (0–127). Pitch class is the note without its octave — all the D♯s share one. Enharmonic spellings (D♯4 and E♭4) name the same pitch two ways.
At other reference pitches
| Reference (A4) | D♯4 frequency | Where you meet it |
|---|---|---|
| 432 Hz | 305.47 Hz | the alternative-tuning circle |
| 440 Hzstandard | 311.127 Hz | the ISO 16 standard — concert pitch |
| 442 Hz | 312.541 Hz | many European orchestras tune a touch sharp |
| 443 Hz | 313.248 Hz | some sharper continental orchestras |
Every row is D♯4 — only the A4 you tune to changes. A frequency scales straight with the reference: D♯4 at 432 Hz is the 440 Hz value times 432⁄440.
Move around
Every D♯
Chords with D♯ in them
D♯ appears in each of these — see the whole chord grid.