F#m9b5

Q: What notes are in the F#m9b5 chord?

The F#m9b5 chord (F# Minor 9b5) contains: F#, A, C, E, G#. Its interval structure is shown above in the Theory section.

Q: How do I build F#m9b5 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 F#m9b5 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 F#m9b5?

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.

F# Minor 9b5

Octaves

Musical context

ChordF#dimTriad

ChordF#m9b5F# Minor 9b5

ArpeggioF# minorBroken triad

ScaleF# minor7 notes

KeyF# minorMinor key

ProgressionAndalusianSequence

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

Theory

General info

Full name: F# Minor 9b5
Symbol: F#m9b5
Root: F#
Quality: Minor 9b5

Chord notes

1F#root

b3Aminor 3rd

b5Cdim 5th

b7Eminor 7th

2G#major 2nd

Functions & resolutions

Stability / tension: Stable — can serve as major tonic
Most common resolutions: BB Major C#C# Major D#mD# Minor
Unstable degrees: 4B
b5C
resolves inward to the 4th
4B
b7E
resolves down to the resolution tonic
Main resolution: F#m9b5source
C#C# Major
Major chord F# is a stable tonic. As tonic it doesn't require resolution, but in a progression context typically moves to IV or V.
Other resolutions: F#m9b5source
Deceptive resolution
D#mD# Minor
As the V degree, a major chord can defy expectations by moving to vi instead of I (deceptive cadence).
F#m9b5source
Modal resolution
EE Major
In modal context, a major chord can freely move to bVII, bIII, or bVI — characteristic of Mixolydian mode.
F#m9b5source
Jazz reharmonization
F#maj7F# 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).
F#m9b5source
Functional resolution
C#C# 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

Root position

v1F#(F#4)Bass

root

v2A(A4)m3from F#

v3C(C5)m3from A

v4E(E5)M3from C

v5G#(G#5)M3from E

Harmony

Compatible scales

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

ScaleC Lydian augmented ScaleE Mixolydian ♭6 ScaleE Harmonic major ScaleF# Romanian minor ScaleF# Ukrainian Dorian ScaleG# Enigmatic scale ScaleG# Phrygian dominant ScaleG# Altered (super Locrian)ScaleA Melodic minor ScaleA Neapolitan major

This chord on guitar 🎸

See how F#m9b5 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

Relative key: D#mD# minor
Dominant: DbDb major
Subdominant: BB major
Key signature: 6 sharps (F#, C#, G#, D#, A#, E#)

What to learn next

ScaleF# 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

F# 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 F#m9b5 chord?

How do I build F#m9b5 on the keyboard?

Which keys is F#m9b5 found in?

What can I substitute for F#m9b5?