Caug

Q: What notes are in the Caug chord?

The Caug chord (C Augmented) contains: C, E, G#. Its interval structure is shown above in the Theory section.

Q: How do I build Caug 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 Caug 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 Caug?

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.

C Augmented

Octaves

Musical context

ChordCaugC Augmented

ArpeggioC majorBroken triad

ScaleC major7 notes

KeyC majorMajor key

ProgressionPop axisSequence

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

Theory

General info

Full name: C Augmented
Symbol: Caug
Root: C
Quality: Augmented

Chord notes

1Croot

3Emajor 3rd

#5G#aug 5th

Functions & resolutions

Stability / tension: Marked tension — unstable, seeks resolution
Most common resolutions: CC Major FF Major
Unstable degrees: #5G#
6A
resolves up to the 6th
Main resolution: Caugsource
CC Major
Augmented Caug has a raised 5th. As a dominant it resolves up a 4th — the raised 5th rising a semitone. Returning to the major of the same root, it instead falls back to a perfect 5th.
Other resolutions: Caugsource
Deceptive resolution
CmC Minor
An augmented chord can resolve to the minor chord of the same root: the raised 5th falls to a perfect 5th and the major 3rd lowers to a minor 3rd.
Caugsource
No resolution needed
In a whole-tone context, the augmented chord can be used as a color chord — without mandatory resolution.
Caugsource
Jazz reharmonization
FF Major
In jazz, aug often acts as a dominant with raised 5th, resolving up a 4th as a V7 substitute.
Caugsource
Functional resolution
EE Major
Due to its symmetry (equal intervals), an augmented chord can resolve to chords a major 3rd apart.

Amharmonic minor

Caugdegree III

The raised 7th of harmonic minor makes the III triad augmented — Caug arises within the key on its own.

CaugV+

Fresolution

As a dominant it resolves a fourth up: the raised fifth (G#) rises a semitone into the tonic's third (A).

Features

Character: Augmented, symmetric and unstable
Characteristic interval: Augmented 5th (#5)
Description: The augmented fifth (#5) is raised a semitone above normal. The chord is symmetric — all three notes are equidistant by major thirds.
Application: Chromatic passing
III in harmonic minor
Unexpected colors