F diminished major 7th chord on bass (FdimMaj7)

Also called or written FdimMaj7, FdimM7, F°M7, F augmented minor seventh or F minor seventh sharp five

F diminished major 7th contains F, A♭, C♭, and E. The 1st-fret shape is the lowest voicing, and an easier inversion at the 1st fret uses an open E string.

FC♭EA♭EADG
Positions on the neck1 of 3
Practice F diminished major 7th chord

How it is built

FRootA♭Minor thirdC♭Diminished fifthEMajor seventh

Formula 1, ♭3, ♭5, 7

Inversions
  • Root positionF–A♭–C♭–EFdimMaj71-2-2-1
  • First inversionA♭–C♭–E–FFdimMaj7/A♭no shape on this instrument
  • Second inversionC♭–E–F–A♭FdimMaj7/C♭no shape on this instrument
  • Third inversionE–F–A♭–C♭FdimMaj7/E0-2-3-1

How do you play an F diminished major 7th chord on bass?

F diminished major 7th is played at the 1st fret as 1 2 2 1: index finger on the E string at fret 1, ring finger on the A string at fret 2, pinky finger on the D string at fret 2 and middle finger on the G string at fret 1.

Full note and interval breakdown
StringFretFingerNote
4 (E)11F (1)
3 (A)23C♭ (♭5)
2 (D)24E (7)
1 (G)12A♭ (♭3)

AdvancedF diminished major 7th requires the ring finger and pinky to fret adjacent strings at the same fret while the index and middle hold the lower fret.

13th fret

F diminished major 7th is played at the 13th fret as 13 14 14 13: index finger on the E string at fret 13, ring finger on the A string at fret 14, pinky finger on the D string at fret 14 and middle finger on the G string at fret 13.

Full note and interval breakdown
StringFretFingerNote
4 (E)131F (1)
3 (A)143C♭ (♭5)
2 (D)144E (7)
1 (G)132A♭ (♭3)

FdimM7/E inversion

F diminished major 7th is played in open position as 0 2 3 1: middle finger on the A string at fret 2, ring finger on the D string at fret 3 and index finger on the G string at fret 1. The E string rings open.

Full note and interval breakdown
StringFretFingerNote
4 (E)openE (7)
3 (A)22C♭ (♭5)
2 (D)33F (1)
1 (G)11A♭ (♭3)

Why it sounds like that

F diminished major 7th is built from the formula 1, ♭3, ♭5, 7. The diminished 5th between F and C♭ creates a tritone that gives the chord its dark color. The major 7th E is a leading tone that resolves upward to F. Compare with F minor 7th flat 5th, which has E♭ instead of E.

What goes wrong with F diminished major 7th?

  • Letting the ring finger flatten onto the 2nd string, which deadens the A♭.
  • Pressing the index finger too hard, causing the 4th string to buzz against the fret.
  • Allowing the pinky to drift sharp, making the 2nd string note sound out of tune.

When to use it

F diminished major 7th works as a passing chord in F minor, often between F minor and F minor 7th. Its tense sound suits jazz ballads and dramatic film cues. Use it to add chromatic motion on the bass.

Changing to and from F diminished major 7th

  • Sliding the shape up one fret to the 2nd fret gives F♯ diminished major 7th.
  • Sliding the shape up two frets to the 3rd fret gives G diminished major 7th.

Which voicing to use

The 1st-fret position places the root F on the 4th string, giving a solid low foundation. The FdimM7/E inversion at the 1st fret puts E in the bass, creating a different color while keeping the same notes.

Other F chords

Common questions

How is F diminished major 7th written?

F diminished major 7th is written F°M7 or FdimM7. The root is F.

What is the difference between F diminished major 7th and F minor 7th flat 5th?

F diminished major 7th has a major 7th (E), while F minor 7th flat 5th has a minor 7th (E♭). The major 7th creates a leading tone that pulls strongly to the octave.

Which inversion of F diminished major 7th is easier for beginners?

The FdimM7/E inversion at the 1st fret is easier because it uses an open E string and lower frets. However, the root position is more common for moving up the neck.