Bdim

B Diminished — tense and unstable by design — built from stacked minor thirds, it begs to resolve.

The keys
C4C5C6
B – D – F
What's inside Bdim
NoteInterval from rootDegree
BRoot1
DMinor 3rdb3
FDiminished 5thb5
Inversions
PositionKeys (low → high)
Root positionB4 – D5 – F5
1st inversionD5 – F5 – B5
2nd inversionF5 – B5 – D6
A working voicing

Split the chord between two hands the way working players do — a solid shell low down, the colour tones up top:

HandKeys
Left (shell)B2 – B3
Right (colour)D5 – F5
Where Bdim lives

As the I chord

Bdim → E → G♭ → Bdim

The classic I–IV–V–I motion with this chord as home.

In a ii–V–I

D♭m7 → G♭7 → Bdim

The strongest cadence in harmony, resolving onto this chord.

Put Bdim under your fingers

Hear every voicing, see the keys light up, and drill it in the interactive Chord & Voicing Lab.

Open the Chord & Voicing Lab →