Chord category
Augmented chords
The augmented chord raises the fifth by a semitone: two major thirds stacked. It sounds bright and floating, with no rest. Written with aug or the + symbol.
Theory
The augmented triad has the root, the major third and the augmented fifth. Being symmetric, three chords share the same notes.
Formula and steps
Degrees
1 – 3 – ♯5
Steps (semitones)
4 – 4
How they are used
It creates tension and impressionistic colour. It works as a step between a major chord and its sixth version, or as an altered dominant.
Progressions (roman numerals)
- I – I+ – I6
- I+ – IV
Example sequences
- C – C+ – C6
- C+ – F
Related chords
Alternative symbols
Written Caug or C+. With the minor seventh it gives C7♯5, an altered dominant common in jazz.