D♯9 / E♭9
9,956.063Hz at concert pitch
Press to hear a pure sine tone at this pitch.
MIDI note
123
Piano key
—
Octave
9
Frequency
9,956.063 Hz
Period
0.1004 ms
Wavelength
0.0345 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♯9 and E♭9) 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) | D♯9 frequency | Where you meet it |
|---|---|---|
| 432 Hz | 9,775.044 Hz | the alternative-tuning circle |
| 440 Hzstandard | 9,956.063 Hz | the ISO 16 standard — concert pitch |
| 442 Hz | 10,001.318 Hz | many European orchestras tune a touch sharp |
| 443 Hz | 10,023.946 Hz | some sharper continental orchestras |
Every row is D♯9 — only the A4 you tune to changes. A frequency scales straight with the reference: D♯9 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.