• Here’s How Music Scholars Classify Chords According To Width

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    In this lesson, I’ll be showing you how music scholars classify chords according to width.

    We’ll be discussing terms like triads, sixths, sevenths, and extended chords and how they are classified in this lesson and the criteria for classification is width. The width of a chord describes the number of tones the chord encompasses.

    Before we get into what we have today, let’s invest the next ten minutes in a review of the term chord.

    “What Is A Chord?”

    There are so many ways to define a chord. These definitions may vary from the simplest to the most complex, however, there are certain keywords that all the definitions of chord have in common.

    Here’s a definition of chords that embraces all these keywords:

     A chord is a collection of three or more related notes (agreeable or not) that is played/heard together or separately.

    Let’s go ahead and breakdown this definition of chord, so that you can have a better understanding of what a chord is.

    “…Collection Of Three Or More…”

    It takes three or more notes to form a chord. A collection of two notes (aka – “intervals“) are not considered to be chords even though Jermaine Griggs calls them “…the building blocks of chords.”

    Chords can be classified according to the number of notes (aka – “note aggregate”) they have…

    • A three note chord is called a triad
    • A four note chord is called a tetrad
    • A five note chord is called a pentad
    • A six note chord is called a hexad
    • A seventh note called is called a heptad

    Consequently, before a collection of notes can be considered as a chord, it must have the features of a triad.

    “…Related Notes…”

    There must be a relationship between the notes of a chord. Not all collections of three or more notes played on the keyboard are considered as chords; only notes that are related are considered as chords.

    The notes of a chord can be related in two ways:

    • Scale relationship
    • Intervallic relationship

    Scale Relationship Of Notes

    The relationship between the notes of a chord, must be based on a particular scale. For example, the notes of the C major chord – which are C E and G:

    …are related by the C major scale:

    A closer look at the C major chord:

    …and the C major scale:

    …shows that the notes of the C major chord:

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

    Attention: Take note that any collection of notes without a scale relationship is not musically fit to be called a chord.

    Intervallic Relationship Between Notes

    The notes of a chord must be related by a given interval, whether in seconds in the case of C-D-E:

    …thirds in the case of C-E-G:

    …fourths in the case of C-F-B:

    …or fifths in the case of C-G-D:

    The notes of the C major chord:

    …have an intervallic relationship. C, E, and G:

    …are related in intervals of thirds.

    From C:

    …to E:

    …is a third.

    From C-E:

    …to G:

    …is also a third.

    In a nutshell, the notes of the C major chord:

    …are related in intervals of thirds.

    Attention: The intervallic relationship between the notes of a chord base on thirds is called tertian harmony. Tertian harmony is the traditional harmony of chords that is commonly used. In this lesson, we’ll be limiting our scope to tertian chords.

    “…Agreeable Or Not…”

    When notes are played together, the relationship between the notes is called harmony. When notes are played harmonically, the outcome is either pleasant or unpleasant.

    Pleasant combination of notes is known as concord while unpleasant/harsh combinations are called discord. Whether a chord is pleasant or unpleasant depends on the intervals its built of.

    Let’s take this lesson to another level by taking a look at the classification of chords according to width.

    The Classification Of Chords According To Width

    In this segment we’ll be looking at how music scholars classify chords according to width. When a chord is played, its width is determined by the number of scale tones it encompasses.

    Suffice it to say that if chords are classified according to width, there will be four chord classes.

    “Check them out…”

    • Triads
    • Sixth chords
    • Seventh chords
    • Extended chords

    Give me the next seven minutes to throw more light on these chord classes.


    Earlier in this course, we learned that a chord consists of “three” or more notes (and I want you to underline the word three.) The least texture a chord can have is a three-note texture, and that’s what music scholars call the triad.

    Going by the formation of chords in thirds (using tertian harmony), a triad consists of the first, third, and fifth tones of the scale. Consequently, triads encompass a fifth interval.

    The C major chord:

    …is a triad because it encompasses five tones of the C major scale:

    …from C to G (a fifth):

    …and has a three note texture.

    There are four triad qualities:

    …which Jermaine Griggs described in his book “4 Steps To Next Level Playing” as the fantastic four.

    Sixth Chords

    The width of sixth chords encompass six tones of the scale. The major and minor sixth chords belong to this class of chords.

    The C major sixth chord:

    …a product of the relationship of the first, third, fifth, and “sixth” tones of the C natural major scale:

    …while the C minor sixth chord:

    …a product of the relationship of the first, third, fifth, and “sixth” tones of the C melodic minor scale:

    Although there are no sixth chords originally in classical music, they are only considered to be inversions of seventh chords (the next class of chords we’re considering in this lesson.)

    Attention: Take note that sixth chords are non-tertian chords because they are not absolutely built in intervals of thirds. The interval between the 5th and 6th tones is a [major] second interval.

    Seventh Chords

    A seventh chord is a chord that encompasses seven degrees of any given scale.

    In the formation of chord, we’re accustomed to starting out with the root and stacking notes in intervals of thirds. Using the C major scale:

    …we can start out with the root (C):

    …stack the third:

    …and the fifth:

    Attention: At the fifth level, a triad is formed.

    The addition of another third above the fifth (G):

    …which is B:

    …produces the C major seventh chord:

    Seventh chords are harmonically advanced than triads and they encompass seven degrees of a scale. In the case of the C major seventh chord:

    …seven degrees of the C major scale:

    …from C to B:

    There are various classes of seventh chords, however these five are commonly used…

    Extended Chords

    Extended chords are chords that contain compound intervals. Compound intervals are intervals that are bigger than an eighth.

    Intervals like ninths, elevenths, and thirteenths are compound intervals that form extended chords. Consequently, ninth, eleventh, and thirteenth chords are extended chords. They are called extended chords because their width exceed the compass of an octave.

    The C major ninth:

    …the C minor eleventh:

    …and the C dominant thirteenth (sharp eleventh):

    …chords are examples extended chords (ninths, elevenths, and thirteenth chords.)

    In a nutshell, all chords that are bigger than the compass of an octave are said to be extended chords.

    Final Words

    Although there’s so much emphasis on the classification of chords according to quality using terms like major, minor, augmented, diminished, dominant, etc., chords can also be classified according to width.

    From what we’ve covered in this lesson, I hope that you can easily put a chord to the width class it belongs; be it a triad, sixth, seventh, or extended chord.

    Thank you so much for the time you’ve invested today. You can also learn more about triads and other chord classes by joining our 16 week chord revival program.

    See you in another lesson.

    The following two tabs change content below.
    Onyemachi "Onye" Chuku (aka - "Dr. Pokey") 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.

    Attention: To learn more about this, I recommend our 500+ page course: The "Official Guide To Piano Playing." Click here for more information.


    { 3 comments… read them below or add one }

    1 Joe

    Are you sure about that Cdom13#11 chord? It looks like a Cmaj13#11. Sorry if i spelled it out wrong, i hope you can understand it. Wouldn’t the B need to to be flattened to make it a Cdom7 13 #11?


    2 Chuku Onyemachi

    Thanks for pointing that error in spelling out to me.


    3 Joe

    Thanks to you i can identify almost any chord, I’ve learned a lot about intervals and chord formation from reading and studying your blogs. Between you, Mr. Griggs and Mr. Powell, y’all are creating a keyboard monster out of me and i thank you all for it. Your welcome.


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