Fdim7

F1A♭♭3C♭♭5E♭♭♭♭7

Three minor thirds stacked. The seventh is doubly diminished, which is why it is written with a double flat.

on ukulele on piano the scale

Every fingering that fits a hand

Fig. 2

120101

moderate

Fig. 3

12010x

open

Fig. 4

120104

moderate

Fig. 5

120404

moderate

Fig. 6

1201xx

open

What is true of it

Fdim7 is F, A♭, C♭ and E♭♭ — 1, b3, b5 and bb7 counted from F.

E♭♭ is a double flat, and it has to be: every letter from F upwards is used once, so the bb7 cannot be written any other way.

The easiest of the 5 fingerings below is 120101: 4 fingers, held at the 1st fret.

2 of them use open strings, which is what makes a shape quiet to change to.

Where its notes are on the neck

Fig. 7 — first 12 frets

The brass dots are F, the root. Everything else is a chord tone with its degree printed in it.

With a different note underneath

first inversion

Fdim7/A♭

420101

second inversion

Fdim7/C♭

x20101

third inversion

Fdim7/E♭♭

xx0101

An inversion is the same chord with a different note lowest. The name changes to a slash name because the bass is what a listener hears as the foundation.

F in other shapes

F7dominant seventh Fmaj7major seventh Fm7minor seventh Fmajor Fmminor Fdimdiminished

Cdim7 C♯dim7 D♭dim7 Ddim7 D♯dim7 E♭dim7 Edim7 F♯dim7 all 374