D♯3 / E♭3
Reviewed for accuracy · Maintained by Justin Evans
D♯3 highlighted — use the view toggle to see all 88 keys.
Piano key
31 of 88
Octave
3
Frequency
155.56 Hz
MIDI number
51
Key color
Black key
Pitch class
D# · Eb · Fbb
What is D♯3?
D♯3 is the D♯ in octave 3 — the 31st key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 155.56 Hz. It sits 9 half-steps below middle C (C4).
To find it, locate any group of two black keys: the white key just to their left is a C. Count down from middle C (C4) 1 octave to reach octave 3, then step to D♯.
Every octave doubles the frequency: the D♯ one octave up sounds at 311.12 Hz and the one below at 77.78 Hz. The same piano key can be written as D#, Eb, Fbb depending on the musical context — same sound, different spelling.
Nearby notes
Every D♯ on the keyboard: