Learn › F Diminished Chord on Piano (Fdim)
New Released in April 2026
F Diminished Chord on Piano (Fdim)
F diminished (Fdim) is spelled F - Ab - Cb: root, minor 3rd and diminished 5th. Its sound is tense, so it rarely stays long before moving on. Here is where Fdim comes from, where it resolves and how to play it with both hands.
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- MIDI keyboard
- Digital or acoustic piano
- Guitar
- Computer, phone or tablet
The F diminished chord and its inversions
Thumb, middle and little finger in the right hand: 1-3-5.
Root position: F Ab Cb
1st inversion: Ab Cb F
2nd inversion: Cb F Ab
- Root position: starts on F, a white key; black keys: Ab
- 1st inversion: starts on Ab, a black key; black keys: Ab
- 2nd inversion: starts on Cb, a white key; black keys: Ab
Train Fdim in a game
In ChordRunner Fdim rides towards your runner between other chords: play it in time. MIDI keyboard or microphone, both work.
Play the demoCommon questions
How do you play Fdim on the piano?
Press F, Ab, Cb together: right hand 1-3-5 with the thumb on F, left hand 5-3-1 with the little finger on F.
What is the difference between Fdim and Fm?
One note. Fm has C on top; Fdim moves it to Cb. The new fifth is what gives Fdim its tense sound.
Where does Fdim go?
Fdim is the vii° chord of Gb major and the ii° chord of Eb minor. It wants to move up a semitone: Fdim → Gb / Gbm, the bottom note rising to the new root.
Can I practise Fdim with a MIDI keyboard or microphone?
Yes. ChordRunner detects a USB MIDI keyboard automatically and also hears an acoustic piano through the microphone. Fdim counts in any position, as long as F, Ab, Cb sound together.
Your instrument is the controller.
ChordRunner is a browser game that teaches piano and guitar chords: a chord appears on screen, you play it on a real instrument, and your runner jumps. MIDI keyboard or microphone, both work.
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