Bbm9b5

General info

Full name

Bb Minor 9b5

Symbol

Bbm9b5

Root

Bb

Quality

Minor 9b5

Chord notes

Functions & resolutions

Typical function in key

viRelative tonic (vi)C# major

Stability / tension

Stable — can serve as major tonic

Most common resolutions

EbEb MajorFF MajorGmG Minor

Unstable degrees

4Eb

b5E

resolves inward to the 4th

4Eb

b7Ab

resolves down to the resolution tonic

Main resolution

Bbm9b5source

FF Major

Major chord Bb is a stable tonic. As tonic it doesn't require resolution, but in a progression context typically moves to IV or V.

Other resolutions

Bbm9b5source

Deceptive resolution

GmG Minor

As the V degree, a major chord can defy expectations by moving to vi instead of I (deceptive cadence).

Bbm9b5source

Modal resolution

AbAb Major

In modal context, a major chord can freely move to bVII, bIII, or bVI — characteristic of Mixolydian mode.

Bbm9b5source

Jazz reharmonization

Bbmaj7Bb Major 7

In jazz, a major chord is enriched to maj7, 6/9, or add9 and can smoothly transition into a ii-V of another key (modulation).

Bbm9b5source

Functional resolution

FF Major

As the IV degree (subdominant), a major chord can resolve to V or directly to I (plagal cadence).

Features

Character

Half-diminished, with an added 9th

Characteristic interval

Diminished 5th (b5), 9th

Description

The minor 3rd, diminished 5th, and minor 7th form a half-diminished seventh chord; the major 9th adds a diatonic extension. The b5 dissonance preserves the instability of the core.

Application

• ii-V in minor (extended)
• Modern jazz
• Substitute for m7b5 with ninth

Voicing & structure

Harmony

Compatible scales

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