A Petrushka chord/C#
The A Petrushka chord chord consists of the A (Perfect unison), A# (Minor second), C# (Major third), D# (Diminished fifth), E (Perfect fifth) and G (Minor seventh) notes, with C# as the bass note.

How to play the A Petrushka chord/C# chord
- Play C# as the lowest bass note in the left hand
- Find A (Root) on the piano keyboard
- Add A# (Minor second) — 1 semitone above A
- Add C# (Major third) — 4 semitones above A
- Add D# (Diminished fifth) — 6 semitones above A
- Add E (Perfect fifth) — 7 semitones above A
- Add G (Minor seventh) — 10 semitones above A
- Press all 7 notes simultaneously to sound the A Petrushka chord/C# chord