The augmented chord is part major, part weirdness. When I first stumbled upon it in the recesses of an old chord book I thought there was a printing error because let's face it, they sound odd.
Augmented chords are major triads with raised (or augmented) 5ths. This means that each interval is a 3rd apart (the aug triad is thus comprised of 'stacked 3rds'). They are not diatonic but rather emerge by virtue of the Harmonic Minor Scale. Take E Harmonic Minor = E F# G A B C D#. The major 7th (D#) is responsible for the
following augmented outcome: G B D# (with its inversions: B D# C and D# G B). From a modal perspective, G B D# = G Ionian #5, B D# G = B Phrygian #3 and D# G B =D# Mixolydian #1. The augmented family includes the following chords: + (or +5 or aug), maj7 #5, maj9 #5, maj11 #5, maj13 #5.
Here are some popular forms with their relevant CAGED shape references beneath:
Like diminished chords, the 'augmenteds' produce an almost eldritch ambience if used in isolation. Brush the Gmaj7 #5 below gently... this is probably the most distinct and recognisable chord in motion picture history.
Now arpeggiate these two triads below four times each. Any fans of Iron Maiden should recognise this bass line (although in this instance it has been transposed up two octaves).
Some augmented chords have starring roles but most often they have less glamorous (but no less interesting) day jobs as substitutions.
Play through the following chord progression based on a ii m - V 7 - vi m7 progression in Em. Shapes are provided below for your convenience.
Am7 - D7 - Em7 - Am7 - D# dim7 - Em7 - Am7 - B7 - Em7
Am7 - D7 - Em7 - Am7 - D# aug - Em7 - Am7 - B aug - G aug - Em7
Notice how the aug chord substitutes the dominant or diminished chords.
This family of chords are Dominant chords with # or v 5ths or 9ths. The altered dominants with raised 5ths are part-dominant/part-augmented e.g. A7 #5. We could
easily use the 7#5 chord in place of the G aug in the progression above i.e. Am7 - D7 - Em7 - Am7 - D# aug - Em7 - Am7 - B aug - G7#5 - Em7.
Equal measures Major and Weirdness (shaken or stirred) produce a peculiar cocktail which is an acquired taste for many. Hopefully I have piqued your curiosity to the extent that you will keep an ear out for the augmented chord and perhaps even find a use for it in your own compositions.
Guy Pople is a music, education and multimedia specialist based in the UK`s North-West. He plays guitars, studies theory and runs St Annes Music in Lytham St. Annes, a one-stop shop for musicians on the Fylde coast of Lancashire. St Annes Music offers professional instruments, recording, tuition and accessories.
His live band Nomad is currently building up their original music. You can catch him
on Virtual Strangers.
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