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B♭ Diminished

Also Known As
What are Enharmonics?B♭ / A♯ Equivalent

Hear the B♭ Diminished chord played for you.

B♭°
B♭ – D♭ – E
Formula:R-m3-d5
Intervals:P1-m3-d5
Scale Degrees:1-b3-b5

Introduction

B♭ Diminished on the piano — Notes: B♭ – D♭ – E
B♭ Diminished chord on the piano

The B♭ Diminished chord is a three-note chord made up of B♭, D♭, and E. It is built from a root, minor third, and diminished fifth.

The Bb Diminished piano chord (Bbdim) consists of the notes Bb, Db, E. It is built by stacking two minor thirds (3 semitones each), giving it a tense, unstable, and dissonant character. Formula: R-m3-d5 | Scale degrees: 1-b3-b5.

Notes

Notes:B♭ – D♭ – E

B♭ Diminished Inversions

PositionNotes
Root PositionB♭ – D♭ – E
1st InversionD♭ – E – B♭
2nd InversionE – B♭ – D♭

Key Signature

The key of Bb Diminished 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.

BEADGCF

Mnemonic: Battle Ends And Down Goes Charles’ Father

Chords in the Key of B♭ Major

These are the diatonic triads built on each degree of the B♭ major scale:

C
D
E
F
G
A
B
C
D
E
F
G
A
B
IB♭ Major (major)
DegreeNumeralChordQuality
1IB♭ MajorMajor
2iiC MinorMinor
3iiiD MinorMinor
4IVE♭ MajorMajor
5VF MajorMajor
6viG MinorMinor
7vii°A DiminishedDiminished

Theory: Intervals

Formula: R-m3-d5
Intervals: P1-m3-d5

The B♭ Diminished is built by stacking intervals from the root note. The formula R-m3-d5 describes the scale degrees used. The intervals P1-m3-d5 show the distance between each note in the chord.

B♭ Diminished — Frequently Asked Questions

What notes are in the Bb Diminished chord?
The Bb Diminished chord contains: Bb (root), Db (minor third), and Fb (diminished fifth). Both intervals are compressed: the minor third is 3 semitones above the root, and the diminished fifth is 6 semitones — a tritone.
How does Bb Diminished differ from Bb Minor?
Bb Minor has a perfect fifth. Bb Diminished lowers the fifth by one semitone to Fb (diminished fifth). That extra compression creates intense harmonic tension — the tritone between root and diminished fifth is the most dissonant interval in Western music.
What is the symbol for the Bb Diminished?
Bb Diminished is written as Bbdim or Bb°. The ° or "dim" symbol means both the third and fifth are minor/diminished. Do not confuse with Bbdim7 or Bbø (half-diminished), which include additional notes.
What are the inversions of Bb Diminished?
First inversion (Bb Diminished/Db): Db–Fb–Bb. Second inversion (Bb Diminished/Fb): Fb–Bb–Db. Diminished triads are used in classical music as the vii° chord — the chord one semitone below the tonic, with strong resolution pull.
How is Bb Diminished used in music?
Bb Diminished most commonly functions as the vii° chord in a major key, creating strong resolution back to the tonic. It also works as a chromatic passing chord between two nearby chords, and in classical music as a brief point of dissonance. Jazz uses the full four-note dim7 more often than the triad.
What songs use diminished chords?
Michelle (Beatles) uses a diminished chord as a chromatic passing chord. Many classical pieces use vii°–I cadences. Jazz standards use dim7 chords as chromatic passing and approach chords. Diminished harmony also appears in flamenco and film music for dramatic tension.

Practice Tips

  • Compare Bb Minor and Bb Diminished: only the fifth changes (Fb vs perfect fifth). Play both back to back — the extra compression is striking.
  • The tritone between Bb and Fb creates maximum tension — practice just this two-note interval to hear its characteristic sound.
  • Bb Diminished most naturally resolves up by half step: play Bbdim then a chord whose root is Bb raised by one semitone.
  • Practice all inversions: Bb–Db–Fb, Db–Fb–Bb, Fb–Bb–Db.
  • Use Bb Diminished as a vii° chord: it is one semitone below Bb# Major — try Bbdim → Bb# Major to feel this powerful classical resolution.
  • In a major key, find where Bb Diminished fits naturally as a passing chord between two diatonic chords a step apart.

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.