B♭ Diminished 7th
Also Known As
Hear the B♭ Diminished 7th chord played for you.
B♭°7
B♭ – D♭ – E – G
Formula:R-m3-d5-d7
Intervals:P1-m3-d5-d7
Scale Degrees:1-b3-b5-bb7
Introduction
The B♭ Diminished 7th chord is a four-note chord made up of B♭, D♭, E, and G. It is built from a root, minor third, diminished fifth, and diminished seventh.
The Bb Diminished 7th piano chord (Bbdim7) consists of the notes Bb, Db, E, G. It is built by stacking three minor thirds, creating a fully symmetrical 4-note chord, giving it a extremely tense and dramatic character, fully symmetrical and harmonically versatile. Formula: R-m3-d5-d7 | Scale degrees: 1-b3-b5-bb7.
Notes
B♭ Diminished 7th Inversions
| Position | Notes |
|---|---|
| Root Position | Bb – Db – E – G |
| 1st Inversion | Db – E – G – Bb |
| 2nd Inversion | E – G – Bb – Db |
| 3rd Inversion | Bb – Db – E – G |
Key Signature
The key of Bb Diminished 7th has 2 flats.
B♭E♭
Order of flats
Flats are added in a fixed order — the reverse of the sharp order. Each new flat key adds the next flat on the list.
B♭E♭A♭D♭G♭C♭F♭
Mnemonic: Battle Ends And Down Goes Charles’ Father
Chords in the Key of Bb Major
These are the diatonic triads built on each degree of the Bb major scale:
C
D
E
F
G
A
B
C
D
E
F
G
A
B
I — B♭ Major (major)
Theory: Intervals
Formula: R-m3-d5-d7
Intervals: P1-m3-d5-d7
The B♭ Diminished 7th is built by stacking intervals from the root note. The formula R-m3-d5-d7 describes the scale degrees used. The intervals P1-m3-d5-d7 show the distance between each note in the chord.
B♭ Diminished 7th — Frequently Asked Questions
What notes are in the Bb Diminished 7th chord?
The Bb Diminished 7th chord (Bbdim7) contains four notes: Bb (root), Db (minor third), Fb (diminished fifth, enharmonically E), and Abb (diminished seventh, enharmonically G). All four notes are spaced exactly 3 semitones apart.
How does Bb Diminished 7th differ from Bb Diminished?
Bb Diminished is a three-note triad (Bb, Db, Fb). Bb Diminished 7th adds Abb/G as the diminished seventh, completing the symmetrical structure.
Why is the Diminished 7th chord symmetrical?
Bbdim7 contains the same pitches as Dbdim7, Edim7, and Gdim7 — all inversions of the same four notes (Bb, Db, E, G). Only three unique dim7 chords exist.
How is Bb Diminished 7th used in music?
Bbdim7 functions as the vii°7 of B/Cb, resolving up by half step to B Major. It works as a chromatic passing chord in many contexts and appears in jazz, classical, and gospel music.
What songs use Diminished 7th chords?
Diminished 7th chords appear in Michelle (Beatles), throughout Chopin and Beethoven, and in jazz standards for chromatic voice leading. Film and musical theatre scores use dim7 for dramatic tension.
How many unique Diminished 7th chords exist?
Only three. Bbdim7 shares its notes with Dbdim7, Edim7, and Gdim7. The other two groups are Cdim7 and Ddim7.
Practice Tips
- Play Bbdim7 and Dbdim7 — same notes rearranged, confirming the three-chord symmetry.
- Bbdim7 resolves to B Major: try Bbdim7 → B for the leading-tone half-step resolution.
- Use as a chromatic passing chord: Bbm7 → Bbdim7 → Am7 for smooth descending voice leading.
- The enharmonic pitches (Bb–Db–E–G) show an alternating black-white pattern on the keyboard.
- Practice all four inversions of Bbdim7 — each sounds equally tense, a unique property of diminished 7th chords.
- Compare Bbdim7 with Bbm7 — both dark, but dim7 is maximum tension while m7 is smooth and soulful.
Related Tools
Chord FinderLook up any chord — see the notes, hear it, and play along.Chord DrillTimed drills to build speed and recognition across all chord types.Practice RoomPlug in a MIDI keyboard and get real-time feedback on every chord and scale.Circle of FifthsVisualize key relationships, relative minors, and key signatures.MIDI MonitorLive MIDI message stream with note names, velocity, and a scrolling staff.