B♭dim

B♭1D♭♭3F♭♭5

Two minor thirds stacked. The fifth is diminished, so it cannot be dropped without losing the chord.

Written the other way round it is A♯dim — the same twelve keys on a piano, a different piece of notation.

on guitar on piano the scale

Every fingering that fits a hand

Fig. 2

3404

easy

Fig. 3

3101

open

Fig. 4

310x

open

Fig. 5

3104

easy

Fig. 6

3464

hard

What is true of it

B♭dim is B♭, D♭ and F♭ — 1, b3 and b5 counted from B♭.

The easiest of the 5 fingerings below is 3404: 3 fingers, held at the 3rd 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 B♭, the root. Everything else is a chord tone with its degree printed in it.

With a different note underneath

first inversion

B♭dim/D♭

x101

second inversion

B♭dim/F♭

x464

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.

B♭ in other shapes

B♭major B♭mminor B♭augaugmented B♭5power chord B♭sus2suspended second B♭sus4suspended fourth

Cdim C♯dim D♭dim Ddim D♯dim E♭dim Edim Fdim all 374