The C Augmented 7th chord is a four-note chord made up of C, E, G♯, and B♭. It is built from a root, major third, augmented fifth, and minor seventh.
Construction
C Augmented 7th = Root + Major 3rd + Minor 6th + Minor 7th = C · E · G♯ · B♭
| Note | Interval | Degree |
|---|---|---|
| C | Root | 1 |
| E | Major 3rd | 3 |
| G♯ | Minor 6th | ♯5 |
| B♭ | Minor 7th | ♭7 |
C Augmented 7th Inversions
| Position | Notes |
|---|---|
| Root Position | C – E – G♯ – B♭ |
| 1st Inversion | E – G♯ – B♭ – C |
| 2nd Inversion | G♯ – B♭ – C – E |
| 3rd Inversion | B♭ – C – E – G♯ |
Key Signature
A Augmented 7th chord is built from symmetrical or ambiguous intervals, so it doesn’t belong to a single key and has no key signature of its own.
Same Notes, Other Names
The notes C – E – G♯ – B♭ aren’t exclusive to this chord. Depending on which note is the bass and how the chord functions, the same pitches also spell:
C Augmented 7th — Frequently Asked Questions
What is the C Augmented 7th chord on piano?
The C Augmented 7th chord contains the notes C – E – G♯ – B♭. On piano, play these notes together to sound the chord.
What notes are in the C Augmented 7th chord?
The C Augmented 7th chord (C+7 or C7#5) contains four notes: C (root), E (major third), G# (augmented fifth), and Bb (minor seventh). It combines an augmented triad with a minor seventh, creating a bright, tense chord with strong upward pull.
How does C Augmented 7th differ from C Dominant 7th?
Both contain C, E, and Bb. The difference is the fifth: C+7 has G# (augmented fifth) while C7 has G (perfect fifth). The raised fifth adds extra tension and an upward pull that the standard dominant 7th does not have.
How does C Augmented 7th differ from C Augmented?
C Augmented is a three-note triad (C, E, G#). C Augmented 7th adds Bb (minor seventh). The minor seventh adds bluesy tension on top of the augmented triad's floating quality, making it a more harmonically complex chord.
How is C Augmented 7th used in music?
C+7 is used as an altered dominant chord, typically resolving to F Major (the same target as C7). The augmented fifth creates even stronger voice leading: G# pulls up to A while Bb pulls down to A, converging on the third of F Major. It is common in jazz, gospel, and blues.
What songs use Augmented 7th chords?
Augmented 7th chords appear in jazz standards like All the Things You Are and in gospel music where altered dominant chords add emotional intensity. Blues guitarists and jazz pianists use +7 chords as colourful dominant substitutes.
What is the difference between augmented 7th and 7#5?
They are the same chord. C+7, C7#5, and Caug7 all refer to C Augmented 7th (C–E–G#–Bb). The different symbols appear in different notation traditions: +7 in jazz lead sheets, 7#5 in classical analysis, aug7 in educational contexts.