B13b9

Q: What notes are in the B13b9 chord?

The B13b9 chord (B 13b9) contains: B, D#, F#, A, C, G#. Its interval structure is shown above in the Theory section.

Q: How do I build B13b9 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 B13b9 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 B13b9?

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.

B 13b9

Octaves

Musical context

ChordB majorTriad

ChordB13b9B 13b9

ArpeggioB majorBroken triad

ScaleB major7 notes

KeyB majorMajor key

ProgressionPop axisSequence

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

Theory

General info

Full name: B 13b9
Symbol: B13b9
Root: B
Quality: 13b9

Chord notes

1Broot

3D#major 3rd

5F#perfect 5th

b7Aminor 7th

b2Cminor 2nd

6G#major 6th

Functions & resolutions

Stability / tension: Stable — can serve as major tonic
Most common resolutions: EE Major F#F# Major G#mG# Minor
Unstable degrees: 4E
b7A
resolves down to the resolution tonic
Main resolution: B13b9source
F#F# Major
Major chord B is a stable tonic. As tonic it doesn't require resolution, but in a progression context typically moves to IV or V.
Other resolutions: B13b9source
Deceptive resolution
G#mG# Minor
As the V degree, a major chord can defy expectations by moving to vi instead of I (deceptive cadence).
B13b9source
Modal resolution
AA Major
In modal context, a major chord can freely move to bVII, bIII, or bVI — characteristic of Mixolydian mode.
B13b9source
Jazz reharmonization
Bmaj7B 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).
B13b9source
Functional resolution
F#F# Major
As the IV degree (subdominant), a major chord can resolve to V or directly to I (plagal cadence).

Substitutions

Tritone substitution: F7F Dominant 7

Features

Character: Dominant, with b9 and 13th
Characteristic interval: Minor 9th (b9), 13th
Description: The minor 9th sharpens dominant tension, while the major 13th adds a consonant extension. The contrast between b9 and 13 makes the chord dense while preserving a clear dominant function.
Application: V13b9 → i in minor
Latin jazz
Advanced jazz cadences

Voicing & structure

Root position

v1B(B4)Bass

root

v2D#(D#5)M3from B

v3F#(F#5)m3from D#

v4A(A5)m3from F#

v5C(C6)m3from A

v6G#(G#6)m6from C

Harmony

Compatible scales

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

ScaleE Harmonic major ScaleC Diminished scale ScaleD# Diminished scale ScaleF# Diminished scale ScaleG# Diminished (half–whole)ScaleA Diminished scale ScaleB Diminished (half–whole)ScaleD Diminished (half–whole)ScaleE Bebop major ScaleF Diminished (half–whole)

This chord on guitar 🎸

See how B13b9 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

Relative key: G#mG# minor
Dominant: F#F# major
Subdominant: EE major
Key signature: 5 sharps (F#, C#, G#, D#, A#)

What to learn next

ScaleB 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

B Chromatic scaleA 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 B13b9 chord?

How do I build B13b9 on the keyboard?

Which keys is B13b9 found in?

What can I substitute for B13b9?