F# Viennese trichord/A#
The F# Viennese trichord chord consists of the F# (Perfect unison), G (Minor second) and C (Diminished fifth) notes, with A# as the bass note.

How to play the F# Viennese trichord/A# chord
- Play A# as the lowest bass note in the left hand
- Find F# (Root) on the piano keyboard
- Add G (Minor second) — 1 semitone above F#
- Add C (Diminished fifth) — 6 semitones above F#
- Press all 4 notes simultaneously to sound the F# Viennese trichord/A# chord