D♯1 / E♭1
Reviewed for accuracy · Maintained by Justin Evans
D♯1 highlighted — use the view toggle to see all 88 keys.
Piano key
7 of 88
Octave
1
Frequency
38.89 Hz
MIDI number
27
Key color
Black key
Pitch class
D# · Eb · Fbb
What is D♯1?
D♯1 is the D♯ in octave 1 — the 7th key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 38.89 Hz. It sits 33 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) 3 octaves to reach octave 1, then step to D♯.
Every octave doubles the frequency: the D♯ one octave up sounds at 77.78 Hz and the one below at 19.45 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: