An augmented chord is a triad built from a root, a major 3rd and an augmented 5th: the 3rd sits four semitones above the root and the 5th sits eight semitones above the root. C augmented is C, E and G#, and its wide, floating sound never quite settles.
What is an augmented chord?
An augmented chord is a major triad with its 5th raised by one semitone. C major is C, E and G; raise the G to G# and you have C augmented: C, E and G#. The 3rd is four semitones above the root, as in a major chord, but the 5th is eight semitones above the root instead of seven, and that extra semitone stretches the chord outward, giving it a strange, floating, dreamlike quality that never quite settles anywhere. Augmented chords are rare in pop and rock but common in jazz, classical music and film scores, where their ambiguity is useful. Because an augmented triad stacks two major 3rds, C to E and E to G#, it is symmetrical: the notes divide the octave into three equal parts of four semitones, so any of the three notes can act as the root and the chord can resolve in several directions. Composers use that ambiguity to slip between keys, or to create a moment of mystery before a resolution.
How augmented chords are built
Start from the major triad and raise the 5th by one semitone. G major is G, B and D, so G augmented is G, B and D#. D major is D, F# and A, so D augmented is D, F# and A#. A major is A, C# and E, so A augmented is A, C# and E# (spelled F in the sharp-only system, since E# is enharmonically F). The rule is the same every time: root, major 3rd four semitones up, augmented 5th eight semitones up. Check the gaps with semitones, not with letter names, because the raised 5th is easy to spell wrong. The symmetry of the augmented triad has a practical consequence for players: the chord repeats every four semitones. C augmented (C, E, G#), E augmented (E, G#, B#) and G# augmented (G#, B#, D##) all contain the same three pitch classes, so the same shape on guitar can be an augmented chord on three different roots depending on which note you treat as the bass. That is why augmented chords are so useful for modulation: the same notes can belong to several keys, and the composer chooses which one by what comes next. The C augmented guitar chord and the G augmented guitar chord show the shape, and the key of C major is the home key to resolve back to.
Worked example — E augmented. E major is E, G# and B. Raise the 5th, B, by one semitone to C, and you have E augmented: E, G# and C. Check the gaps: E to G# is four semitones, a major 3rd, and E to C is eight semitones, an augmented 5th. E augmented is often used as a passing chord between E major and A minor: the raised 5th, C, is the 3rd of A minor, so the chord leans toward Am. Play E, Eaug, Am and hear the bass stay still while the top note pulls the harmony forward. The E augmented guitar chord shows the shape, and the chord finder builds any augmented triad.
How to practise augmented chords
Augmented chords are best learned as a colour between two stable chords. Practise the movement, not just the shape.
- Play C, Caug, F, listening for the G# in the middle chord pulling upward toward A, the 3rd of F major.
- Play E, Eaug, Am, and notice how the C in Eaug is already the 3rd of the Am chord you are heading for.
- On piano, play an augmented triad in root position, then move the whole shape up four semitones and identify the new chord: the notes will be the same set in a different order.
- Build the augmented triads on C, E and G# and write out their notes, checking that each one stacks two major 3rds.
- Use the interval calculator to check the augmented 5th above any root before you build the chord.
Common mistakes
- Raising the 3rd instead of the 5th — Raising the 3rd of a major chord by a semitone gives a minor chord with a wrong note, not an augmented chord. Only the 5th moves: the 3rd stays exactly four semitones above the root.
- Confusing augmented with sharp 5 — They are the same sound, but the spelling matters. In an augmented chord the top note is the raised 5th of the root, so C augmented is C, E and G#, not C, E and Ab, even though G# and Ab are the same pitch.
- Using an augmented chord as a tonic — An augmented triad is too unstable to be a home chord. It works as a passing chord, a dominant colour or a modulation device, but a song that starts and ends on an augmented chord will sound unfinished.
Quick reference
For example, the augmented triad chord on C is C – E – G#, and every other row follows the same pattern. Keep this table beside you while you practise. It lists the augmented triad chord on six common roots, and because the root, major 3rd and augmented 5th pattern is identical on every root, learning one row properly means you can work out the other five by counting semitones from the root note.
| Root | Augmented Triad notes |
|---|---|
| C | C – E – G# |
| G | G – B – D# |
| D | D – F# – A# |
| A | A – C# – F |
| E | E – G# – C |
| F | F – A – C# |
The pattern in the table is the whole lesson in miniature: the same intervals, the same shape, a different starting note. Practise the rows in a random order rather than top to bottom, so you are building each augmented triad chord from the intervals instead of memorising a list.
Frequently asked questions
What notes are in an augmented chord?
The root, the major 3rd and the augmented 5th. C augmented is C, E and G#. The 3rd sits four semitones above the root and the 5th sits eight semitones above the root, one semitone wider than the perfect 5th of a major chord.
Why do augmented chords sound strange?
Because the augmented 5th is an unusual interval that does not appear in the major or natural minor scales, and because the chord is symmetrical, with two equal major 3rds stacked. The ear cannot tell which note is the root, so the chord feels directionless and floating.
What is the difference between augmented and major chords?
One note: the 5th. A major chord has a perfect 5th, seven semitones above the root, while an augmented chord has an augmented 5th, eight semitones above the root. The root and the 3rd are identical in both.
Where are augmented chords used?
Mostly in jazz, classical music and film scores, as passing chords and modulation devices. They also appear in the dominant chord of a minor key: E augmented can act as a colourful dominant leading to A minor.
Can an augmented chord resolve in more than one direction?
Yes, because it is symmetrical. C augmented can resolve to F major (the G# rises to A), to A minor (the G# is already close to A) or to E major, depending on which note the composer treats as the leading note. That flexibility is the chord's main strength.