How to Play Cdim7 on Piano
The C Diminished 7th chord sounds dramatic and unstable. It stacks 4 notes: C – Eb – Gb – Bbb.
Three stacked minor thirds, dividing the octave into four equal parts. Any of its notes can act as the root, which makes it the classic pivot for changing key abruptly.
Notes in Cdim7
| Note | Interval | Finger |
|---|---|---|
| CC4 | Root | 1 |
| EbEb4 | Minor 3rd | 2 |
| GbGb4 | Diminished 5th | 3 |
| BbbBbb4 | Major 6th | 5 |
How to Play
Right Hand
Place your thumb (finger 1) on C. Use finger 2 on Eb, finger 3 on Gb, and finger 5 on Bbb.
Where it sits
2 notes of this chord (Eb, Gb) are on black keys, so play it a little further back on the keys than an all-white shape.
Press all 4 keys at the same time. Keep your wrist relaxed and your fingers curved. The blue dots on the piano below show exactly which keys to press — they turn green when you play the right note.