C7♯5 (augmented seventh)

4-note augmented 7th on CC, E, G♯, A♯.

Press to hear the chord strummed low to high.

A dominant seventh built on an augmented triad — the raised fifth makes it strain even harder to resolve.

The notes

Pitches taken from the first fingering below — click any note to open its frequency page.

Interval formula

DegreeNoteWhat it is
1Croot
3Emajor third
♯5G♯sharp fifth (augmented)
♭7A♯flat seventh (dominant)

The formula reads in semitones above the root (C): 1, 3, ♯5, ♭7. A voicing may leave a tone out — often the fifth — but never adds one from outside this set.

Guitar fingerings · 4

2134
open position
3fr14132
from fret 3
8fr1234
from fret 8
10fr1423
from fret 10

Ukulele fingerings · 4

12
open position
1432
open position
5fr1423
from fret 5
8fr2314
from fret 8

Read a diagram top-down: the thick bar is the nut, dots are where to press (the number is which finger), means play the open string, means don't play it. A bar across strings is a barre.

Other C chords

7♯5 (augmented seventh) chords on every root