Augmented Chords on Guitar

What an augmented chord is

A major chord is root, 3rd and 5th (1 3 5). An augmented chord raises the 5th by one half step, so the formula is 1 3 ♯5. C is C E G, and C augmented is C E G♯. The word augmented means widened: the gap between the 3rd and the 5th grows from 3 semitones to 4.

The chord symbol has three common spellings, and all mean the same chord:

• Caug
• C+
• C(♯5)

The sound is tense and floating. A major chord feels settled, and an augmented chord feels as if it wants to move somewhere. That makes it a colour more than a home chord.

In a major or minor chord the 5th is a stable note. In an augmented chord it is raised, which is where the tension comes from. The ♯5 of A+ is E♯, the same pitch as F, and the ♯5 of E+ is B♯, the same pitch as C.

The chord that has three names

Count the semitones in C E G♯. C to E is 4, E to G♯ is 4, and G♯ up to the next C is 4. The three notes split the octave into three equal parts. Only one other common chord does this, the diminished 7th, which splits it into four (see diminished chords).

Because the steps are equal, you can start on any of the three notes and get the same pitches:

• C+ is C E G♯
• E+ is E G♯ B♯ (B♯ is the pitch C)
• A♭+ is A♭ C E (A♭ is the pitch G♯)

So C+, E+ and A♭+ are one chord with three possible roots. On the guitar the lowest note usually suggests the name. A shape with C at the bottom reads as C+, and the same notes with E at the bottom read as E+.

The symmetry also helps on the neck. Move any augmented shape up 4 frets and the three pitches stay the same, only their order changes.

Augmented shapes to learn

The strings from low to high are E A D G B E. Below, x means do not play the string and the numbers are frets, written from the 6th string to the 1st.

• C+ (x 3 2 1 1 0): the root is on the 5th string. Think of an open C chord (x 3 2 0 1 0) with the open G string pressed at fret 1, so the 5th G becomes G♯. The open top string is E, the 3rd.
• E+ (x x 2 1 1 0): the root is on the 4th string. A short, light shape that works well in a high register.
• D+ (x x 0 3 3 2): open D for the root, then A♯, D and F♯. Four strings are enough, so mute the two lowest.
• A+ (x 0 3 2 2 1): open A in the bass, then F, A, C♯ and F. It is an A major shape with the 5th raised, so E moves up to F.

All four use the same idea: take a major chord and push the 5th up one fret. If you know your open chords, you can often make the augmented version by moving one finger.

Augmented chords as passing chords

Most songs use an augmented chord for one job: linking two diatonic chords by a half step in one voice. The raised 5th is the moving note, and it climbs by a half step into the next chord.

In C major the 5th of C is G. In C+ it becomes G♯, and from G♯ it climbs a half step to A:

This works when a major chord moves to the chord a 4th above it or to its relative minor. Give the augmented chord one beat or one bar, then resolve it.

Augmented chords also come from minor keys. The harmonic minor scale has a raised 7th, and the chord built on its 3rd degree is augmented. In A harmonic minor that is C+ (C E G♯), which comes straight out of the scale. A dominant 7th with a raised 5th, written G7♯5, is a related colour for the V chord resolving to C. For that kind of chord see 7th chords.

Reading and naming an augmented chord

Name the chord after its lowest sounding note unless the music says otherwise. When the bass note is not the one the name suggests, a slash chord is the clear way to write it: C+/E means the C+ chord with E in the bass, the same pitches as E+. The idea is explained in slash chords.

Quick checks when you read a chart:

1. A + or aug after the letter means 1 3 ♯5.
2. A ♯5 in brackets, as in C(♯5), is the same chord.
3. A 7 before the ♯5 means a 7th is added, as in C7♯5.
4. A sus chord replaces the 3rd, while an augmented chord keeps the 3rd and raises the 5th. See sus chords for the other colour chord.

Playing tips

• Strum only the strings in the shape. Extra strings pull the sound away from the augmented colour.
• All three notes are equal in weight, so play the root a touch louder and the ear hears a name for the chord.
• Do not hold it long. An augmented chord is a transition, and two beats of it usually feel like plenty.
• Practise moving from a normal chord to the augmented chord and back, changing one finger. This trains your ear to hear the raised 5th as a half-step climb.
• Check any shape you build in the chord finder to see that the name matches the notes.