D b5
The D b5 chord consists of the D (Perfect unison), F# (Major third) and G# (Diminished fifth) notes.

How to play the D b5 chord
- Find D (Root) on the piano keyboard
- Add F# (Major third) — 4 semitones above D
- Add G# (Diminished fifth) — 6 semitones above D
- Press all 3 notes simultaneously to sound the D b5 chord