D2
Reviewed for accuracy · Maintained by Justin Evans
D2 highlighted — use the view toggle to see all 88 keys.
Piano key
18 of 88
Octave
2
Frequency
73.42 Hz
MIDI number
38
Key color
White key
Pitch class
D · C## · Ebb
What is D2?
D2 is the D in octave 2 — the 18th key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 73.42 Hz. It sits 22 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) 2 octaves to reach octave 2, then step to D.
Every octave doubles the frequency: the D one octave up sounds at 146.84 Hz and the one below at 36.71 Hz. The same piano key can be written as D, C##, Ebb depending on the musical context — same sound, different spelling.
Nearby notes
Every D on the keyboard: