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New Released in April 2026

F Diminished 7th Chord on Piano (Fdim7)

Fdim7, the F diminished 7th chord, stacks Ab, Cb and Ebb on top of F. Four keys, formula 1 b3 b5 bb7: the Fdim triad plus Ebb. Below: the four positions, fingering, a three-note voicing and where Fdim7 goes next.

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Fdim7 F Ab Cb Ebb

F diminished 7th chord inversions

A seventh chord has four notes, so it has four positions. Each one is still Fdim7.

Fdim7 F Ab Cb Ebb

Root position: F Ab Cb Ebb

Fdim7 Ab Cb Ebb F

1st inversion: Ab Cb Ebb F

Fdim7 Cb Ebb F Ab

2nd inversion: Cb Ebb F Ab

Fdim7 Ebb F Ab Cb

3rd inversion: Ebb F Ab Cb

Playing Fdim7 with each hand

HandFAbCbEbb
Right hand1 (thumb)235 (little)
Left hand5 (little)321 (thumb)

Land all four fingers at once. If Ebb is quieter, the little finger is too flat.

Fdim7 without the fifth

Fdim7 F Ab Ebb

Root, third, seventh: F Ab Ebb. It is the shape to learn first, and it moves smoothly to the next chord.

Fdim7 compared with the other 7th chords on F

One note changes and the chord gets a new name.

ChordNotesWhat changes
F7 F A C Ebmajor 3rd, minor 7th
Fmaj7 F A C Emajor 3rd, major 7th
Fm7 F Ab C Ebminor 3rd, minor 7th
Fm7b5 F Ab Cb Ebminor 3rd, flat 5th, minor 7th
Fdim7 F Ab Cb Ebbminor 3rd, flat 5th, 7th one key lower again

Where Fdim7 goes

  • Fdim7 is the vii°7 chord of F# minor: it pulls up one key, Fdim7 → F# / F#m.
  • Every note is three keys above the one before, so Fdim7, Abdim7, Bdim7 and Ddim7 use the same four keys.
  • That even spacing is why Fdim7 sounds tense, dramatic and can lead to several different chords.
  • Cb is the same key as B.
  • Ebb is the same key as D.

vii°7 → i: Fdim7 → F#m

How to practise Fdim7

  1. Play F, Ab, Cb, Ebb slowly in root position and say "Fdim7" each time.
  2. Climb the four positions: F Ab Cb Ebb, then Ab Cb Ebb F, Cb Ebb F Ab and Ebb F Ab Cb, and back down.
  3. Loop Fdim7 → F#m until the change into and out of Fdim7 is clean.
  4. Finally meet it in random order between other chords, with a check on every note.

Short daily rounds fix Fdim7 in memory faster than one long practice a week.

ChordRunner showing a chord block while hands play the piano

Practise Fdim7 by playing

Knowing Fdim7 on paper is step one. ChordRunner makes you find it fast, mixed with other chords. MIDI keyboard or microphone, both work.

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Common questions

What is the difference between Fdim7 and Fdim?

Fdim7 adds one note to the Fdim triad: Ebb, the diminished seventh. That fourth note is what makes it a seventh chord.

What are the inversions of Fdim7?

Root position F Ab Cb Ebb, 1st inversion Ab Cb Ebb F, 2nd inversion Cb Ebb F Ab and 3rd inversion Ebb F Ab Cb. Every position is still Fdim7.

Where does Fdim7 go?

Fdim7 is the vii°7 chord of F# minor: it pulls up one key, Fdim7 → F# / F#m. Every note is three keys above the one before, so Fdim7, Abdim7, Bdim7 and Ddim7 use the same four keys.

Can I practise Fdim7 with a MIDI keyboard?

Yes. In ChordRunner a USB MIDI keyboard is detected automatically, and an acoustic piano works through the microphone. Fdim7 counts in any inversion, as long as F, Ab, Cb, Ebb sound together.

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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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