About C#aug — triad voicings
C#aug is C#, E# and A — C# with the fifth raised a semitone.
It sounds stretched, and suspended between keys. Its commonest job is passing between a major triad and its sixth or seventh, with the raised fifth as a single voice walking up.
C#aug notes and formula
| C# | E# | A |
|---|---|---|
| 1 | 3 | ♯5 |
Passing chord — it belongs to no key in particular.
Also written C#+, C#(#5) or C# augmented. The same chord either way; which spelling you meet depends on who wrote the chart.
How to play C#aug
Three notes on one string set. No seventh, so nothing is claimed about the chord beyond its quality.
Thin on their own, excellent over a bass line or against someone else’s harmony.
C#aug has 45 of them, on the top three strings, the top four strings, the low-middle three, the high-middle three, the middle four strings, the bottom three strings, strings 5-3-2-1, the bottom four strings and strings 6-4-3-2, from open position up to the 14th — every inversion the chord has: C# in the bass, E# in the bass and G## in the bass. The one to learn first is the G## shape at the nut, which is the easiest grip here.
6 of them sit on the top four strings, so you can run the inversions up one set without changing strings — which is the whole reason to learn them as a family rather than as separate grips.
Start with xxx665 — only 3 fretted notes and low, at the 5th fret. None of the shapes for C#aug uses an open string, so every one of them is movable; the lowest sits at the 1st fret. None of them needs a barre. Together they cover the neck from the 1st fret to the 11th.
| Frets | Where | Bass | Top | Hand |
|---|---|---|---|---|
| xx3221 | 1st fret | E#, 1st inversion | E# | all fretted |
| x4322x | 2nd fret | C#, root position | C# | all fretted |
| x4x665 | 4th fret | C#, root position | A | all fretted |
| x4766x | 4th fret | C#, root position | E# | all fretted |
| xxx665 | 5th fret | C#, root position | A | all fretted |
| 98766x | 6th fret | C#, root position | E# | all fretted |
| 9-x-11-10-10-9 | 9th fret | C#, root position | C# | all fretted |
| x-x-11-10-10-9 | 9th fret | C#, root position | C# | all fretted |
What to play over C#aug
Every note of C#aug is in C# whole tone and C# altered.
Chords near C#aug
Change one note of C#aug and you have C# (the sharp fifth becomes a fifth), C#maj7#5 (add the major seventh) or C#aug7 (add the flat seventh).
C#aug is a augmented chord — root, major third, sharp fifth. Augmented chords on every root.
On C#aug’s sound and use this page follows Stefan Kostka, Dorothy Payne & Byron Almén, Tonal Harmony (McGraw-Hill, 8th ed., 2018). The shapes and the derived voicings come from different places, and both are explained in where the chords and the theory come from.