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

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