F dim
The F dim chord consists of the F (Perfect unison), G# (Minor third) and B (Diminished fifth) notes.

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