You arrived at this page because you’re interested in learning about the instability of the minor sixth chord.
When compared to other minor chord types, the minor sixth chord is rarely used and this is because it’s an unstable chord. So, we’ll be focusing on the instability of the minor sixth which is its uniqueness.
However, I’ll like us to refresh our minds on the sixth minor chord before we get started.
A Quick Review On The Minor Sixth Chord
The minor sixth chord is basically a minor triad with an added tone. The tone that is added to the minor triad to form the minor sixth chord is always a “major sixth” above the root of the minor triad.
For example, the D minor sixth chord can be formed using the D minor triad:
…and adding the sixth tone — which is a major sixth above the root of the given minor triad.
A major sixth above D:
…is B:
Consequently, adding B:
…to the D minor triad:
…produces the D minor sixth chord:
Attention: The major sixth interval is the interval between the first and third tones of the natural major scale.
Following the same procedure, any minor sixth chord can be formed on the keyboard.
“Check Out All The Minor Sixth Chords On The Keyboard…”
C minor sixth chord:
C# minor sixth chord:
D minor sixth chord:
Eb minor sixth chord:
E minor sixth chord:
F minor sixth chord:
F# minor sixth chord:
G minor sixth chord:
G# minor sixth chord:
A minor sixth chord:
Bb minor sixth chord:
B minor sixth chord:
Now that we’ve refreshed our minds on the minor sixth chord, let’s proceed to learning about it’s uniqueness — its instability.
Exposed: The Instability Of The Minor Sixth Chord
Before we go any further, let’s break down the minor sixth chord into its intervallic components.
Intervallic Components Of The Minor Sixth Chord
The intervallic components of a chord are the intervals that a chord can be broken down into. For example, the C major triad:
…can be broken down into the following intervals:
C-E:
…a major third interval.
E-G:
…a minor third interval.
C-G:
…a perfect fifth interval.
“Alright, Let’s Breakdown The Minor Sixth Chord Into Its Intervallic Components…”
Using the C minor sixth chord as a reference:
…the minor sixth chord can be broken down into the following intervals:
C-Eb:
…a minor third interval.
C-G:
…a perfect fifth interval.
C-A:
…a major sixth interval.
Eb-G:
…a major third interval.
Eb-A:
…an augmented fourth interval.
G-A:
…a major second interval.
Altogether, the minor sixth chord can be broken down into the following intervals:
Minor third interval
Perfect fifth interval
Major sixth interval
Major third interval
Augmented fourth interval
Major second interval
Attention: The minor sixth chord consists of an augmented fourth interval — also known as the tritone.
Final Words
The minor sixth chord is not commonly used in harmony because of its inherent tension derived from the tritone (augmented fourth interval).
However, in certain harmonic pictures where the tension is needed and at the performer’s discretion, the minor sixth chord can fit in and sound desirable.
See you in the next lesson.
