Bbdim

Bbdim is Bb, Db and Fb, a diminished triad. The shape this page opens on is written x1232x, lowest string first.

Note by note. Bb is the root, Db is the minor third and Fb is the flat fifth.

Also written Bb°, Bbo or Bb diminished. The same chord either way; which spelling you meet depends on who wrote the chart.

There are 5 common shapes for Bbdim on the guitar, and 49 derived voicings in the triad family.

One note away. Change a single note of Bbdim and you have Bbm (with one note moved), Bbdim7 (with one note added), Bbm7b5 (with one note added) or BbmMaj7b5 (with one note added).

In which keys. Every note of Bbdim belongs to Ab minor (the ii°) and B major (the vii°).

The common shapes, written lowest string first: x1232x, 64x65x, xx89x9, x-13-11-x-11-12, x-13-14-15-14-x.

Under the hand. None of the shapes for Bbdim uses an open string, so every one of them is movable; the lowest sits at the 1st fret. None of them needs a barre. Together they cover the neck from the 1st fret to the 15th.

Triad. Three notes across one string set. Bbdim has x1232x, xxx320, x423xx, xx232x, x4232x, xx2320, 0423xx, xxx656.

Tensions. A shell of Bbdim, root, third and seventh, leaves a string free, and the tones that belong over it are the 11 (Eb) and the b13 (Gb).

What kind of chord this is. Bbdim is a diminished chord — root, minor third, flat fifth. diminished and half-diminished chords on every root, and what they are for.

The common shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.