Bb7b5

Q: What notes are in the Bb7b5 chord?

The Bb7b5 chord (Bb 7b5) contains: Bb, D, Fb, Ab. Its interval structure is shown above in the Theory section.

Q: How do I build Bb7b5 on the keyboard?

Take the root and add the remaining chord tones following the interval formula. The highlight shows chord content, while the inversion control changes which chord tone is in the bass.

Q: Which keys is Bb7b5 found in?

The chord acts as a diatonic degree in several keys — they are marked on the circle of fifths in the "Harmonic context" block.

Q: What can I substitute for Bb7b5?

A substitution depends on harmonic function and voice leading, not only on shared tones. Computed options appear in the "Substitutions" block and should be checked in context.

Bb 7b5

Octaves

Musical context

ChordBb majorTriad

ChordBb7b5Bb 7b5

ArpeggioBb majorBroken triad

ScaleBb major7 notes

KeyBb majorMajor key

ProgressionPop axisSequence

How the chord relates to the scale, mode, key and progression.

Theory

General info

Full name: Bb 7b5
Symbol: Bb7b5
Root: Bb
Quality: 7b5

Chord notes

1Bbroot

3Dmajor 3rd

b5Fbdim 5th

b7Abminor 7th

Functions & resolutions

Typical function in key: VDominant (V)Eb major
Stability / tension: High tension — requires resolution
Most common resolutions: EbEb Major CmC Minor
Unstable degrees: 3D
4Eb
resolves up to the resolution tonic
4Eb
b5E
resolves inward to the resolution tonic
6G
b7Ab
resolves down to the tonic 3rd
Main resolution: Bb7b5source
EbEb Major
Dominant 7th Bb7 naturally resolves up a 4th to Eb. It is the tritone between the chord's 3rd and 7th that creates this pull.
Other resolutions: Bb7b5source
Deceptive resolution
CmC Minor
Instead of the tonic, the dominant resolves to the vi degree. Creates surprise and is often used to extend a musical phrase.
Bb7b5source
Modal resolution
AbAb Major
In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.
Bb7b5source
Jazz reharmonization
E7E Dominant 7
Tritone substitution: Bb7 can be replaced by E7 (a tritone away). Both chords share the same tritone between the 3rd and 7th, resolving to the same tonic.
Bb7b5source
Functional resolution
Bbsus4Bb Sus4
The dominant can resolve beyond the tonic: moving to IV (subdominant) or to a suspension (sus4) are common alternatives in pop and folk music.

Substitutions

Tritone substitution: E7E Dominant 7

Features

Character: Dominant, with a diminished 5th
Characteristic interval: Diminished 5th (b5), Minor 7th (b7)
Description: The diminished fifth replaces the perfect fifth, adding a tritone to the dominant tension. Sharper than a regular dom7.
Application: Tritone substitution
Jazz ii-V-I
Altered blues

Voicing & structure

Root position

v1Bb(Bb4)Bass

root

v2D(D5)M3from Bb

v3Fb(Fb5)M2from D

v4Ab(Ab5)M3from Fb

Harmony

Compatible scales

All chord tones are contained in these scales — use them for improvisation.

ScaleD Whole tone scale ScaleE Whole tone scale ScaleG# Whole tone scale ScaleA# Whole tone scale ScaleC Whole tone scale ScaleF# Whole tone scale ScaleD Hungarian minor ScaleD Lydian augmented ScaleE Enigmatic scale ScaleE Altered (super Locrian)

This chord on guitar 🎸

See how Bb7b5 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

Relative key: GmG minor
Dominant: FF major
Subdominant: EbEb major
Key signature: 2 flats (Bb, Eb)

What to learn next

ScaleBb Chromatic scaleScale to improvise over this chord PracticeChord trainerLock the fingering into muscle memory ProgressionChord progressionsHow this chord works inside real progressions

Recommended for you

Bb Chromatic scaleA scale related to this chord

Bb Enigmatic scaleA scale related to this chord

Bb Altered (super Locrian)A scale related to this chord

Practice

Keyboard Trainer

Reinforce it in practice — play and name notes on the interactive keyboard.

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Test yourself

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What notes are in the Bb7b5 chord?

How do I build Bb7b5 on the keyboard?

Which keys is Bb7b5 found in?

What can I substitute for Bb7b5?