Symmetrical Chords on Guitar
Symmetrical chords have a unique place in music theory, which results in a unique application to the guitar (and fretted instruments in general). This article is the first in a series, that is will take a look at symmetrical chords, where they come from and how we can apply them to guitar.
To start with, we will look at a little bit of theory. In the next few parts we will look at some practical applications - i.e. playing!
Try not to skip ahead ;)
Building Standard Triads
Before we look at building symmetrical chords, let’s look at how basic chords are made. Basic major and minor chords are built using intervals of a major third and a minor third, placed one after the other.
We call them “triads” because we have three notes in the chord.
You can think of an interval as a musical distance - a distance of a specific number of frets - on your guitar. A major third is a distance of 4 frets (for example, fret 1 to fret 5) and a minor third is a distance of 3 frets (for example, fret 1 to fret 4).
Major chords have a major third (M3) followed by a minor third (m3). For example, C major:
C E G C to E = 4 frets = M3 E to G = 3 frets = m3
Minor chords have a minor third followed by a major third. For example A minor:
A C E A to C = 3 frets = m3 C to E = 4 frets = M3
So we could write a formula for major and minor chords, based on the intervals they contain: Major chord = M3 m3 Minor chord = m3 M3
One Step Further - 7th Chords
To build 7th chords, we take these intervals and add an extra major or minor third to the pattern:
Minor / Major 7 chords sound pretty ‘out there’ and are not as common as the first three chords.
Symmetrical Chords
Symmetrical chords are when we build a chord using only a single type of interval. In the previous section we built chords using combinations of M3 and m3 intervals. Now we are going to look at some chords using only M3 intervals and only m3 intervals.
Using two minor thirds: A C Eb A to C is a minor third = m3 C to Eb is a minor third = m3
This gives us a diminished triad
Using two major thirds: C E G# C to E is a major third = M3 E to G# is a major third = M3
And this gives us an augmented triad.
We can take both of these one step further and make 7th chords:
Using three minor thirds: A C Eb Gbb A to C is a minor third = m3 C to Eb is a minor third = m3 Eb to Gbb is a minor third = m3
This gives us a diminished 7th triad
Using three major thirds: C E G# B# C to E is a major third = M3 E to G# is a major third = M3 G# to B# = M3.
B# is C, so we can’t add an extra M3 interval to this chord - we end up back where we started!
Note: There are chords named augmented 7ths. These are major 7 or dominant 7 chords, where the 5th is raised to be an augmented 5th. They are not symmetrical chords, so we will not be looking at them. I just wanted to clear that up to prevent possible confusion.
So to quickly summarise our symmetrical chords and their intervals: Diminished: m3 m3 Diminished 7th: m3 m3 m3 Augmented: M3 M3
So that is the theory behind how symmetrical chords are formed in theory. In the next article we’ll take a look at some practical applications of this!