C♯ Augmented Chord (C#aug, Dbaug) on Piano
The C#aug chord (C# augmented) is built from 3 notes: C# – E# – G##. It is also written as Dbaug.
Play these notes on a MIDI keyboard, your computer keyboard, or the on-screen keys and ChordKeys will name the chord back to you.
Notes and intervals
| Note | Degree | Interval from C# | Semitones |
|---|---|---|---|
| C# | 1 | root | 0 |
| E# | 3 | major 3rd | 4 |
| G## | #5 | augmented 5th | 8 |
Inversions
Rearranging which note sits at the bottom gives you 3 playable voicings of the same chord. Inversions let you move between chords with less hand movement.
| Voicing | Notes | Bass note |
|---|---|---|
| Root position | C# – E# – G## | C# in the bass |
| 1st inversion | E# – G## – C# | E# in the bass |
| 2nd inversion | G## – C# – E# | G## in the bass |
How the augmented chord is built
Every augmented chord uses the same interval formula: 1 (0 semitones), 3 (4 semitones), #5 (8 semitones). Starting on C# and applying that formula produces C#, E#, G##. Learn the formula once and you can build a augmented chord on any of the twelve roots.
Other chords on C#
Augmented chords on other roots
Frequently asked questions
What notes are in a C#aug chord?
A C#aug chord contains the notes C#, E#, G##. Those are the 1, 3, #5 degrees measured from the root note C#.
How do you play C#aug on piano?
Place your thumb on C#, then add E# and G## above it. With a right hand in root position the common fingering is 1–3–5.
Is C#aug the same as Dbaug?
Yes. C#aug and Dbaug are enharmonic equivalents — they sound identical and use the same piano keys. Which spelling you use depends on the key you are playing in.