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C#aug(Augmented Chord)

A major triad with a raised fifth. Creates a mysterious, unsettled sound.

Notes
C# – F – A
Intervals (semitones)
0 – 4 – 8
Type
Triad

🎹 C#aug on Piano

Press highlighted keys simultaneously to play the C#aug chord.

R
C#(Root (R))
2
F(Major 3rd)
3
A(Augmented 5th (♯5))

🎸 C#aug on Guitar

The C#aug chord uses notes C#, F, A. Build a voicing by finding these notes on any strings — root on the 6th string is a common starting point for barre chord shapes.

Interval Analysis

DegreeInterval NameSemitonesNote in C#
RootRoot (R)0C#
3rdMajor 3rd4F
5thAugmented 5th (♯5)8A

About the C# Augmented Chord

The C#aug chord (C# Augmented) consists of 3 notes: C#, F, A. A major triad with a raised fifth. Creates a mysterious, unsettled sound.

To build any augmented chord, apply intervals of 0, 4, 8 semitones above the root. Starting from C#: the notes land on C#, F, A.

Playing C#aug on Piano

Press C#, F, A simultaneously. In root position, C# is lowest. First inversion places F in the bass for a lighter sound; second inversion uses A as the bass note.

Common Chord Progressions Using C#aug

  • I–IV–V: C#aug – F#aug – G#aug (blues and rock)
  • I–V–vi–IV: C#aug – G# – A#m – F# (pop staple)
  • I–vi–IV–V: C#aug – A#m – F# – G# (50s progression)

The C#aug Chord in Context

As a augmented chord, C#aug is the tonic (I) in the key of C# major. It also appears as the IV chord in G# major, and as the V chord in F# major — making it one of the most important chords across all of Western music.

Other C# Chords

C#
Major
C#m
Minor
C#7
Dominant 7th
C#maj7
Major 7th
C#m7
Minor 7th
C#dim
Diminished

Augmented Chord in All 12 Keys

CaugC#augDaugD#augEaugFaugF#augGaugG#augAaugA#augBaug
🎹 Virtual Piano
Play C#aug on piano
🎸 Virtual Guitar
See on the fretboard
🎵 C# Scale
Notes that fit C#aug
🎶 Songs
Find songs using C#aug

FAQ

C#aug Chord — Frequently Asked Questions

What notes are in the C#aug chord?
The C# Augmented chord contains: C#, F, A. These notes are derived by applying the augmented interval formula (0–4–8 semitones) to the root note C#.
What is the C#aug chord used for?
A major triad with a raised fifth. Creates a mysterious, unsettled sound. The C#aug chord is used across pop, rock, jazz, and classical music. As the I chord in the key of C# major, it functions as the most stable resting point in progressions.
How do you play C#aug on piano?
On piano, play C#, F, A simultaneously. In root position, C# is the lowest note. Inversions move the bass note up — first inversion has F lowest, second inversion has A lowest.
How many notes are in a augmented chord?
A augmented chord has 3 notes: C#, F, A (in C#). It is a triad — the most fundamental chord type.
What is the difference between C# major and C# minor?
The C# major chord (C#–F–G#) uses a major third (4 semitones), giving it a bright, happy sound. The C# minor chord (C#–E–G#) uses a minor third (3 semitones), giving it a darker, emotional sound.
What key does C#aug belong to?
C#aug naturally serves as the I chord in the key of C# major. It also appears as IV in the key of G# major, and as V in the key of F# major.
Can I play C#aug on ukulele?
Yes. The ukulele uses GCEA tuning with 4 strings. The C#aug chord notes (C#, F, A) can be fretted on a ukulele, though the shapes differ from guitar due to the 4-string layout and shorter scale.
What chords go well with C#aug?
In the key of C# major, C#aug pairs naturally with F# major (IV), G# major (V), and A#m (vi). The classic I–IV–V (C#aug–F#–G#) is the foundation of blues, country, and rock.
What is a chord inversion of C#aug?
An inversion places a non-root note in the bass. C#aug root position: C# in bass. First inversion: F in bass. Second inversion: A in bass. Inversions create smoother bass line movement without changing the harmony.
How do I memorize the notes in a augmented chord?
Remember the formula: 0–4–8 semitones from root. For C#aug: start on C#, add 4 semitones, then 8 semitones. Practicing this across all 12 roots builds instant recognition of any augmented chord.