About the B flat diminished seven chord
B flat diminished seven is used in D flat Ultra Locrian, where its notes spell the i° chord. Think of it as a B♭ diminished seventh chord.
Its notes are B♭, D♭, F♭, and A♭♭. The intervals are a minor third, a diminished fifth, and a diminished seventh.
Also called °7 and fully diminished. A sharp diminished seven spells the same notes enharmonically. In shorthand it is commonly written Bbdim7.
Inversions
B flat diminished seven (root position)
Notes and intervals
| 1 | BbB♭ | Root |
|---|---|---|
| 2 | DbD♭ | Minor 3rd |
| 3 | FbF♭ | Diminished 5th |
| 4 | AbbA♭♭ | 7d |
Shapes
Chromatic
Circle of Fifths
Keys that use B flat diminished seven
B flat diminished seven is diatonic to these keys, where its notes spell the chord shown.
Other B flat chords
Simpler triads
Suspended
Sixths and sevenths
Extensions
Altered
Functional relationships
These chords are where this one most naturally comes from and resolves to inside a key.
Relative major
The relative major uses the same notes and key signature, so it works as a brighter home base.
Parallel major
The parallel major keeps the same root note but raises the third, giving the same key a brighter, happier sound.
Dominant
The dominant is a fifth above the root, and it builds tension that pulls strongly back to this chord.
Subdominant
The subdominant is a fourth above the root (a fifth below), and it usually leads on to the dominant or back home.
Tritone substitution
The tritone substitution stands in for this chord's dominant with a dominant seventh a half step above the root, which slides down by a half step to resolve here.
Embed this chord
