C# Augmented

Notes:C# – F – A
Formula:R-M3-A5
Intervals:P1-M3-A5
Scale Degrees:1-3-#5

Introduction

The C# augmented piano chord (C#aug, C#+) consists of three notes: C#, F, and A. It is formed by two stacked major thirds: C# to F (4 semitones) and F to A (4 semitones). This symmetrical structure gives the augmented chord its distinctive tense, floating, and unresolved sound. The C# augmented chord is commonly used in jazz and classical music as a chromatic passing chord, a dominant substitute with a raised fifth, or to create harmonic tension before resolution.

Enharmonic equivalent: C♯ is enharmonically equivalent to D♭. See Db Augmented.

Notes

Notes:C# – F – A

C# Augmented Inversions

PositionNotes
Root PositionC#4 – F4 – A4
1st InversionF4 – A4 – C#5
2nd InversionA4 – C#5 – F5

Key Signature

The key of C# Augmented has 7 sharps: F♯, C♯, G♯, D♯, A♯, E♯, B♯.

F♯C♯G♯D♯A♯E♯B♯

Theory: Intervals

Formula: R-M3-A5
Intervals: P1-M3-A5

The C# Augmented is built by stacking intervals from the root note. The formula R-M3-A5 describes the scale degrees used. The intervals P1-M3-A5 show the distance between each note in the chord.

C# Augmented — Frequently Asked Questions

What notes are in the C# Augmented chord?

The C# Augmented chord contains three notes: C# (root), E# (major third), and G## (augmented fifth — one semitone higher than a perfect fifth). The augmented fifth is what gives this chord its tense, unresolved quality.

How does the C# Augmented chord differ from C# Major?

The only difference between C# Augmented and C# Major is the fifth: C# Major has a perfect fifth, while C# Augmented raises it by one semitone to an augmented fifth (G##). This single change transforms a stable, resolved chord into one full of tension and forward motion.

What is the symbol for the C# Augmented chord?

The C# Augmented chord is written as C#aug or C#+. The "aug" or "+" symbol indicates the augmented fifth. In lead sheets and chord charts, both notations are common — C#aug appears in classical and jazz contexts while C#+ is common in pop and rock.

How do I use the C# Augmented chord in music?

Augmented chords create tension and a sense of motion. The most common uses are: (1) as a chromatic passing chord between the I and IV chords (e.g., C# → C#aug → IV), (2) over a chromatic bass line moving upward, and (3) in jazz as a substitute for dominant chords. The augmented fifth wants to resolve up by one semitone.

What are the inversions of the C# Augmented chord?

The C# Augmented chord has a unique property: all three of its inversions are enharmonically equivalent. Because each note is separated by exactly 4 semitones (a major third), rotating the notes always produces the same interval structure. C#aug in root position, first inversion, and second inversion all sound the same quality.

What songs use augmented chords?

Augmented chords appear in Oh! Darling (Beatles), which uses Aaug as a chromatic passing chord, and in many jazz standards as chromatic dominant substitutes. Stevie Wonder and Elton John frequently use augmented chords for their characteristic tension-building quality.

Practice Tips

  • Compare C# Major and C# Augmented back to back — press C#–E#–(perfect 5th) then C#–E#–G## to hear how the raised 5th creates tension.
  • The augmented fifth (G##) wants to resolve upward by one semitone — practice C#aug → resolving chord to feel this motion.
  • All augmented chord inversions sound the same quality — explore this by playing root, first, and second inversions in sequence.
  • Use C#aug as a chromatic passing chord: C# Major → C#aug → (IV chord) to hear its most common musical function.
  • Augmented chords divide the octave into three equal parts — C#aug, E#aug, and G##aug are all the same chord (enharmonic). Verify this by playing each.
  • In jazz, try using C#aug as a substitute for the V7 chord — the aug5 acts as a chromatic approach to the I chord's root.