C# Augmented Chord
Mysterious, dreamy sound
C#aug - Basic position
What is a C#aug chord?
An augmented chord stacks the root, major 3rd and raised 5th (#5). Like the diminished chord, both interval gaps are equal — but in this case, two major 3rds. The result is symmetrical and rootless-feeling: any of the three notes could plausibly be the root. Augmented chords feel suspended, dreamy, lifting — never fully resolved.
Notes in the chord: C# – F – A
Intervals: Root, 3, #5 (measured from the root)
Where C#aug fits in a key
C#aug appears as the I in C# major.
Common progressions with C#aug
I-V-vi-IV — in C# major
C# → G# → A#m → F#
I-IV-V — in C# major
C# → F# → G#
I-vi-IV-V — in C# major
C# → A#m → F# → G#
When to use a augmented chord
C#aug works as a chromatic lift out of C# on the way to F#. Use augmented chords as a chromatic step inside a I → I+ → IV motion (e.g. C → Caug → F) — the raised 5th becomes the major 3rd of F, creating smooth voice leading. They appear constantly in jazz, blues turnarounds (the V+ before a I), and any genre wanting that suspended, lifting quality (think Beatles 'Oh Darling' intro, or 60s Bond themes).
Common substitutions for C#aug
- •Augmented 7 (7#5) — adds a flat 7 for a dominant-augmented sound that resolves like V7
- •Whole-tone-derived voicings — augmented + 9 is rooted in the whole-tone scale
- •Plain major — drop the #5 if the moment calls for stability
Improvisation Basics
Learn to solo over progressions
Practice with Improvisio
Use C#aug in a progression and see which scales work best.
Try it in the trainer