F7#9

Q: What notes are in the F7#9 chord?

The F7#9 chord (F 7#9) contains: F, A, C, Eb, G#. Its interval structure is shown above in the Theory section.

Q: How do I build F7#9 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 F7#9 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 F7#9?

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 7#9

Octaves

Musical context

ChordF majorTriad

ChordF7#9F 7#9

ArpeggioF majorBroken triad

ScaleF major7 notes

KeyF majorMajor key

ProgressionPop axisSequence

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

Theory

General info

Full name: F 7#9
Symbol: F7#9
Root: F
Quality: 7#9

Chord notes

1Froot

3Amajor 3rd

5Cperfect 5th

b7Ebminor 7th

#2G#aug 2nd

Functions & resolutions

Stability / tension: High tension — requires resolution
Most common resolutions: BbBb Major GmG Minor
Unstable degrees: 3A
4Bb
resolves up to the resolution tonic
6D
b7Eb
resolves down to the tonic 3rd
#2Ab
4Bb
resolves to the resolution tonic
Main resolution: F7#9source
BbBb Major
Dominant 7th F7 naturally resolves up a 4th to Bb. It is the tritone between the chord's 3rd and 7th that creates this pull.
Other resolutions: F7#9source
Deceptive resolution
GmG Minor
Instead of the tonic, the dominant resolves to the vi degree. Creates surprise and is often used to extend a musical phrase.
F7#9source
Modal resolution
EbEb Major
In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.
F7#9source
Jazz reharmonization
B7B Dominant 7
Tritone substitution: F7 can be replaced by B7 (a tritone away). Both chords share the same tritone between the 3rd and 7th, resolving to the same tonic.
F7#9source
Functional resolution
Fsus4F 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: B7B Dominant 7

Features

Character: Dominant, with an augmented 9th
Characteristic interval: Minor 7th (b7), Augmented 9th (#9)
Description: The augmented 9th is enharmonically equivalent to a minor 3rd and sounds alongside the chord’s major 3rd. Their chromatic clash creates sharp tension characteristic of blues and rock.
Application: Blues rock (Jimi Hendrix "Purple Haze")
Funk
Jazz fusion

Voicing & structure

Root position

v1F(F4)Bass

root

v2A(A4)M3from F

v3C(C5)m3from A

v4Eb(Eb5)m3from C

v5G#(G#5)P4from Eb

Harmony

Compatible scales

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

ScaleA Hungarian minor ScaleC# Harmonic major ScaleE Double harmonic ScaleE Persian scale ScaleE Byzantine ScaleC Diminished scale ScaleC Bebop melodic minor ScaleD# Diminished scale ScaleF Diminished (half–whole)ScaleF Bebop minor

This chord on guitar 🎸

See how F7#9 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

Relative key: DmD minor
Dominant: CC major
Subdominant: BbBb major
Key signature: 1 flat (Bb)

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 F7#9 chord?

How do I build F7#9 on the keyboard?

Which keys is F7#9 found in?

What can I substitute for F7#9?