Triads and Harmony

Welcome back! I'm excited to continue our journey into the world of triads on guitar. In previous posts, we covered the basics of triads and their benefits for guitar players of all levels. If you haven't read them you can find them here: Learn Triads to Connect Chords and Become a Better Rhythm Player, A Deeper Look at Triads and A Deeper Look at Triads - Part 2

Today, we're going to take a closer look at how triads change as we move through a chord progression using a technique called voice leading. It might sound like a fancy term, but it's really just a way of understanding how each note in a chord moves to the next chord in the progression and using as little motion as necessary. By paying attention to these movements, we can get a better sense of the different options available to us when creating new musical ideas as well as getting to the essence of what is happening when the chord changes.

What's really cool about looking into this is that it can help us develop a stronger connection between our ears and our instrument. As we listen to and play through different chord progressions, we start to build an intuitive sense of how the notes in each chord relate to one another and how they will move to the notes in the next chord.

Let's jump in and start connecting the dots between what you hear, understand, and play on your guitar through understanding triads and harmony!

Voices

So let's talk about triads and voices! When you play a triad on your guitar, each individual note in that chord is called a voice. Take a C Major triad, for example, which consists of the notes C, E, and G. We label these notes with specific names - the C is called the Root, the E is the 3rd, and the G is the 5th. These labels help us understand the different parts of the triad and how they fit together.

Now, when you're playing a series of chords in a progression, each voice in a chord usually does one of three things as it moves from one chord to another. It either stays the same, moves lower (which is called "falling"), or moves higher (which is called "rising"). This is what we call voice leading, and it's an important concept to understand if you want to really get a grasp on how chords change. By understanding how each voice relates to each chord and the motion of each voice when the chord changes, you can start to connect what you hear to what you see on your guitar fretboard.

Diatonic Triads

Diatonic (From Diatonic Definition & Meaning - Merriam-Webster)

adjective

dia·ton·ic ˌdī-ə-ˈtä-nik 

: of, relating to, or being a musical scale (such as a major or minor scale) comprising intervals of five whole steps and two half steps

For the examples in this post, I will use diatonic triads in the key of E Major. Here are the triads we will be working with.

Root Motion and Bass Motion

As a rhythm guitarist, the movement of the root note and the movement of the bass note in a chord progression are important concepts to understand. Root motion refers to the movement of the root note of each chord in a progression, while bass motion refers to the movement of the lowest note of each chord.

Root motion is often used to describe the harmonic movement of a chord progression. For example, a common chord progression such as I-V-vi in the key of C (CMaj, G/B, Amin) would have a root motion of C-G-A. Understanding root motion can help you identify patterns in chord progressions, which can be helpful when creating your own progressions or improvising.

On the other hand, bass motion is more related to the overall sound and feel of a progression. By changing the lowest note of a chord, you can change the chord's inversion, which can create a different sound and feel. Inversions can be used to create smoother voice leading and to add variety to a progression. For example the same chord progression as above would have the bass motion of C-B-A.

While root motion and bass motion are related concepts, they each have their own distinct characteristics and importance in understanding harmony.

The Circle of Fourths / Fifths

To better understand patterns of one chord changing to another it is helpful to use the circle of fourths and fifths.

Foot Motion of a Fourth

Let's start with something fun - checking out what happens when we move from one chord to another. For example, if we play an E Major chord and then move to an A Major chord, which is called a I - IV chord progression in the key of E. When we switch from E Major to A Major, two voices in the chord move up and one stays the same. The root of the E Major stays the same and becomes the 5th of the A Major. The 3rd of the E Major goes up a half step and becomes the root of the A Major. The 5th of the E Major goes up a whole step and becomes the 3rd of the A Major. When we use a I - IV chord progression, the sound of the chords rises because two notes move up. And, even if you play the same chords in different octaves on your guitar, you can still hear that rising sound. Cool, right?

Just as a I - IV chord progression 'rises', any chord change that has a root motion of a fourth with have the exact same characteristics. Let's look at some other chord changes in the key of A Major

ii - V (F# minor - B Major)

Let's take a look at what happens when we play an F# minor chord and move to a B Major chord in the key of E Major. This progression has a root motion of a 4th. In this case, one voice stays the same, one rises, and one falls. The F# in the F# minor chord remains the same and becomes the 5th of the B Major chord. The A in the F# minor chord rises a whole step and becomes the root of the B Major chord. The C# in the F# minor chord falls a half step and becomes the 3rd of the B Major chord. This combination of voice movement gives the overall sound of the chords rising and falling simultaneously. Even if voice leading isn't being used and you play an F# minor to B Major in different octaves on the guitar, you will still be able to hear this unique characteristic of the sound.

iii - vi (G# minor - C# minor)

Similarly G# minor to C# minor has the root motion of a fourth.

V - I (B Major - E Major)

As does B Major to E Major

In all the examples of two chords that have a root motion of a fourth the voices move in exactly the same way creating a rising sound.

Root Motion of a Fifth

Let's now check out what happens when we play a I chord and go to a V chord in a chord progression. In the key of E, this would be E Major to B Major. This progression has a root motion of a 5th, and in contrast to the I-IV chord progression we just looked at, two voices fall. The root note of the E Major chord falls a half step and becomes the 3rd of the B Major chord. The 3rd of the E Major chord falls a whole step and becomes the 5th of the B Major chord. The 5th of the E Major chord stays the same and becomes the root note of the B Major chord. Since two voices fall when playing a I-V chord progression, it gives the overall sound of the chords falling. This falling sound is characteristic of a chord progression with a root motion of a fifth.

Here are some additional examples of chord changes in the key of E Major that have a root motion of a fifth.

I-V (E - B)

Just as a I - V chord progression 'falls', any chord change that has a root motion of a fifth with have the exact same characteristics. Let's look at some other chord changes in the key of A Major

ii - vi (F# minor - C# minor)

IV - I (A Major - E Major)

vi - iii (C# minor - G# minor)

Making it Practical

As you continue to explore the world of triads on your fretboard, pay close attention to the root motion of each chord progression you play. By doing so, you'll gain a deeper understanding of the relationship between chords and the sound they create. With this knowledge, you'll be able to confidently create and play your own music, taking your guitar playing to the next level. So don't be afraid to experiment and try new things. With practice and persistence, you'll soon discover the joy and satisfaction that comes from mastering the art of triads and understanding their role in modern harmony. Keep on playing.