D1
Reviewed for accuracy · Maintained by Justin Evans
D1 highlighted — use the view toggle to see all 88 keys.
Piano key
6 of 88
Octave
1
Frequency
36.71 Hz
MIDI number
26
Key color
White key
Pitch class
D · C## · Ebb
What is D1?
D1 is the D in octave 1 — the 6th key of the 88 on a full-size piano, counted from the bottom. In standard tuning it sounds at 36.71 Hz. It sits 34 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 73.42 Hz and the one below at 18.36 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: