• How To Determine If A Chord Is Stable Or Not In 5 Seconds Or Less

    in Piano

    If you are interested in learning how to determine if a chord is stable or not, then you’ve arrived at the right page.

    In this lesson, we’ll be doing a thorough breakdown on the elements that determines the stability of a chord, and at the end of this lesson, you’ll be able to tell if a chord is stable or unstable in five seconds or less.

    It is important for us to discuss briefly on the stability of a chord but before we do that, let’s do a quick review on the concept of chords.

    “What Is A Chord?”

    A chord according to Jermaine Griggs, is a collection of three or more related notes (agreeable or note) that may be played or heard together.

    To give you a clearer picture of what a chord is, I would want us to highlight some of the essential keywords in the definition of a chord.

    “…three or more…”

    This keyword gives us the note aggregate of a chord. It’s important to note that less than three notes cannot make a chord. So, it’s three notes or more that produces a chord.

    “…related notes…”

    It is the relationship between the notes of a chord (aka – “chord tones”) that determines if a collection of three or more notes is a chord or not. There are two relationships that can exist between chord tones:

    • Scale Relationship
    • Intervallic Relationship

    For example, the notes of a C major triad:

    …which are C:

    …E:

    …and G:

    …are related by the C natural major scale:

    C, E, and G:

    …are the first, third, and fifth tones of the C natural major scale.

    Also, there is an intervallic relationship between the notes of the C major chord. From C to E:

    …is a third, and so is E to G:

    So the C major chord is built on third intervals, consequently, it’s called a tertian chord.

    “Just Before We Move On…”

    There are three classes of chords according to width.

    We have triads which are chords of three notes, which consists of a root, a third, and a fifth tone.

    There are also seventh chords which are basically four note chords. A seventh chord consists of the root, third, fifth, and seventh tones of a given scale.

    And there are also extended chords. These are chords that exceed the compass of one octave.

    Although, there are three widths of chords; triad, sevenths, and extended chords, we’ll be focusing on seventh chords in this lesson.

    A Short Note On The Stability Of A Chord

    A stable chord is a chord that when played, have no tendency to move. A stable chord has this sense of repose and calmness. While an unstable chord has this tendency to move to a stable chord when played. Stable chords sound pleasant while unstable chords sound harsh.

    In terms of stability, there are two classes of chords:

    • Consonant Chords
    • Dissonant Chords

    In consonant chords, there is an agreeable relationship between the notes whereas in dissonant chords the relationship is between inagreeable notes, hence, the outcome of the relationship between the notes is unpleasant.

    Pay attention to this…

    It is important to know that the stability of a chord depends on the intervals the chord is made up of (aka – “its intervallic components”).

    So using the intervallic component of a chord, you can be able to decipher whether the chord is stable or not. And I’ll show you how in the next segment.

    How To Determine The Stability Of A Chord

    According to music scholars, dissonant intervals includes diminished and augmented intervals. And for the most part, the interval that every musician must look out for that usually tampers with the stability of a chord is the diminished fifth interval which is an inverted tritone.

    Before we proceed, let’s take a look at some of the intervallic properties of the diminished fifth interval.

    A Short Note On The Diminished Fifth Interval

    The diminished fifth interval is also known as a tritone, and can be formed by shrinking a perfect fifth interval by a half step. For example, a perfect fifth interval which is a product of the relationship between the first and fifth tones of any given major scale, which in this case could be C and G:

    The shrinking of the C perfect fifth interval either by raising C:

    …by a half step to C#:

    …to produce C#-G:

    …or to lower G:

    …by a half step to Gb:

    …to produce C-Gb:

    …produces what is known as the devil’s interval, and nothing good was found in it, and that’s because of its dissonant nature.

    Now most chords that contain the diminished fifth interval tend to be unstable. So when played, they inherit the property of the diminished fifth interval.

    Also, one other vital fifth interval that you should look out four is the augmented fifth interval.

    The presence of the augmented fifth interval in a chord tampers with the stability of a chord. So if a chord contains any of these fifth intervals (the diminished fifth or the augmented fifth interval) such a chord loses its stability.

    And I’ll be showing you how to determine the stability of a chord in five seconds or less.

    Here’s how it works…

    When given any chord (whether triad or seventh chord) look out for possible fifth intervals. For example, in the D minor triad:

    …there’s just one fifth interval in the chord, and that’s D to A:

    Considering that it is a perfect fifth interval, D-A:

    …is a stable chord.

    And then on the other hand, the D augmented triad:

    …which consists of D:

    …F#:

    …and A#:

    …there’s an augmented fifth interval between D and A#:

    Consequently, the D augmented triad is an unstable chord.

    The same thing is obtainable in seventh chords, however you must learn how to break down the seventh chords into mutual fifth intervals.

    For example give the C minor seventh chord:

    …you can break it down into two mutual fifth intervals, C-G:

    …and Eb-Bb:

    …and both are perfect fifth intervals. Consequently, the C minor seventh chord:

    …is a stable chord.

    Let’s check out the C dominant seventh chord:

    The C dominant seventh chord consists of two mutual fifth intervals; C-G:

    …and E-Bb:

    C-G:

    …is a perfect fifth interval, and E-Bb:

    …is a diminished fifth interval.

    Consequently, the C dominant seventh chord is an unstable chord, and this is because of the diminished fifth intervallic components formed between E and Bb:

    Final Words

    So given any chord at sight, I’m pretty sure that you can be able to determine whether it is a stable or an unstable chord.

    See you in the next lesson!

     

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    Chuku Onyemachi

    Head of Education at HearandPlay Music Group
    Onyemachi "Onye" Chuku is a Nigerian musicologist, pianist, and author. Inspired by his role model (Jermaine Griggs) who has become his mentor, what he started off as teaching musicians in his Aba-Nigeria neighborhood in April 2005 eventually morphed into an international career that has helped hundreds of thousands of musicians all around the world. Onye lives in Dubai and is currently the Head of Education at HearandPlay Music Group and the music consultant of the Gospel Music Training Center, all in California, USA.




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