C#aug7

C# Augmented 7th

Octaves

Musical context

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

Theory

General info

Full name
C# Augmented 7th
Symbol
C#aug7
Root
C#
Quality
Augmented 7th

Chord notes

1C#root
3E#major 3rd
#5Aaug 5th
b7Bminor 7th

Functions & resolutions

Typical function in key
vii°Leading tone (vii°)D major
Stability / tension
High tension — requires resolution
Most common resolutions
Unstable degrees
3F
4F#
resolves up to the resolution tonic
#5A
6A#
resolves up to the tonic 3rd
6A#
b7B
resolves down to the tonic 3rd
Main resolution
C#aug7source
F#F# Major
Dominant 7th C#7 naturally resolves up a 4th to F#. It is the tritone between the chord's 3rd and 7th that creates this pull.
Other resolutions
C#aug7source
Deceptive resolution
D#mD# Minor
Instead of the tonic, the dominant resolves to the vi degree. Creates surprise and is often used to extend a musical phrase.
C#aug7source
Modal resolution
BB Major
In rock and blues, the dominant often moves to bVII or IV instead of the tonic, creating a modal flavor.
C#aug7source
Jazz reharmonization
G7G Dominant 7
Tritone substitution: C#7 can be replaced by G7 (a tritone away). Both chords share the same tritone between the 3rd and 7th, resolving to the same tonic.
C#aug7source
Functional resolution
C#sus4C# 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

Features

Character
Dominant, with an augmented 5th
Characteristic interval
Augmented 5th (#5)
Description
The major 3rd and minor 7th preserve dominant structure, while #5 replaces the perfect 5th and intensifies semitone voice leading into the next chord.
Application
  • Altered dominant V
  • Dominant resolution to major or minor
  • Jazz voice leading

Voicing & structure

Root position

v1C#(C#4)Bass
root
v2E#(E#4)M3from C#
v3A(A4)M3from E#
v4B(B4)M2from A

Harmony

Compatible scales

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

This chord on guitar 🎸

See how C#aug7 looks on guitar.

Explore

Circle of fifths

Highlighted major keys contain this chord among their diatonic harmonies.

CAmGEmDBmAF#mEC#mBG#mF#D#mDbBbmAbFmEbCmBbGmFDmDbmajor
Relative key
Dominant
Subdominant
Key signature
5 flats (Bb, Eb, Ab, Db, Gb)

Practice

Keyboard Trainer

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Frequently Asked Questions