Understanding chord progression theory is more difficult than memorizing chords.

Fair enough?  I’d like to think so.

Yet, chord progression theory can bring clarity and help make chord memorization much easier, if you take the time to learn it.

Besides, you want to become a better music theorist, right?

The good news: We can improve our chord vocabulary in the process of becoming better students of our instrument.

We’ll do that by learning the basics of chord progression theory within a guitar context.

To help us do so, this content is available in two parts:

1. Textbook-Style Article (what you’re reading now)
2. Premium Screencast Walkthrough

The article is free of charge, as is all of our blog content. For screencast information, see the end of this article.

Guitar scale theory shows us that chords are grouped based on particular keys. In other words, every chord you play has its own key.

For example, the key of E major has its own grouping of chords that fall within that key.

They include the following:

From the chart below you can begin to identify different chord groupings which form what we would consider “common” guitar chord progressions:

While this list is not comprehensive, the source does a good job of pooling easily recognized chord progressions from the key of E major.

Source: guitar-chords.org.uk

Even if you’ve only spent a small amount of time with the guitar, you’ve likely played through the E, A, and B progression. The other two progressions listed, though slightly more advanced, are also easily recognizable.

As we begin to see chords as members of a key, we can start memorizing common chord progressions and even learn to identify their keys on the fly.

Further, we’ve established that part of the reason most chord progressions fit together is because all chords within that progression share the same key.

And that key comes from a corresponding scale where, instead of single notes, you’re dealing with full chords where each chord’s root note represents a scale degree (more on that later).

"Many chord progressions fit together (resonate) because they share a common key.

However, not all chord progressions need to contain only chords that are found within the same key.

Take the E, G and A progression, for example.

Though this progression is commonly used, the G chord is not found within the listing of chords in the key of E major. Thus, as a guitar player, you can use chord progression keys as a starting point, but you need not rigidly adhere to them.

Just note that many of the common chord progressions you’ll hear are drawn entirely out of a shared key.

This is how an entire song can have its own key. It’s simply derived from the chord combination and resolving note.

For example, if a song sounds resolved on the E note, and three of the four chords used are found in the key of E major, then it’s a safe bet to say that that song is in the key of E (more on resolving notes later).

Lining Up Chords by the Root Note

We need to couple our understanding of a chord’s key with some basic chord composition.

Specifically, we’ll learn to identify a chord’s root note.

There are several ways to explain root notes (also called the tonic) in plain English.

We’ll look at two of them:

1. The Root Position: Building on the Bass Note
2. Tertian Harmonic Theory

This sounds frightfully complex, but it’s not as difficult as it sounds.

Let’s begin with a simple bass note.

Learning to Identify the Bass Note of a Chord

When a chord is in the root position, we understand a chord’s root note to be the lowest note in the chord.

In other words, a chord is most often named after and represented by the lowest bass note.

Thus, when you have a stack of vertical notes, as in the following tab, it’s reasonable to default to viewing the lowest of those notes as the root or “tonic” of the chord.

Most of the time you’ll be right.

This is probably the easiest and most straightforward way to understand root notes.

However, it’s not always the case that you can simply look at the lowest note and find the chord’s tonic.

If we consider the theory behind triads and inversions, it’ll become clear that we need to be more thorough.

Briefly, let’s define a triad:

Triads are chords made up of three notes stacked in third intervals.

Because of these intervals, the order of notes in a triad can vary.

For example, you can have three distinct arrangements of triadic chords, which are formally called voicings:

1. Root Position
2. First Inversion
3. Second Inversion

When a chord is arranged in either a first or second inversion, the lowest note in the chord no longer represents the root of that chord. Consider the following sheet:

For all three chords, the notes are actually the same (C, E, and G). However, the root C is only the lowest note in the arrangement marked “Root Position.”

Tertian harmonic theory can also be helpful when it comes to understanding this concept.

Tertian Harmony and Triads

In his book, Twentieth-Century Music Theory and Practice, Edward Pearsall gives Tertian harmony a lean, digestible definition:

               "A harmony consisting of thirds."

And where have we seen this before?

Right.

The most ideal example of this is a triad.

Pearsall continues:

"Tertian chords include triads and sevenths But do not always function according to tonal protocol."

In other words, there can be instances where you’ll have Tertian harmony but, without strictly triadic chords present. Yet in most cases, a triad will be the primary instance of Tertian harmony that you’ll need to be away of.

Thus, it’s essentially the theoretical grid-work behind triadic chords.

Recall our three triadic chord arrangements from earlier:

1. Root Position
2. First Inversion
3. Second Inversion

And if we translate each note:

• Root Position: C – E – G
• 1st Inversion: E – G – C
• 2nd Inversion: G – C – E

Remember our diagram?

These notes are a perfect match.

In all three cases, the root of the chord is the C note but, in only one case is the C note the lowest in the chord.

If there is a case where you need to find your root note and it’s not the lowest note in the chord, chances are that this is the theoretical concept you’re dealing with.

The “Ghost” Note

Another instance where the lowest note in a chord is not the root, is when you have a ghost or optional note.

Take the following F chord:

I’ve seen the F chord played this way pretty regularly, but that lowest note is a C and not an F.

If we’re not careful, we’ll assume that note to be the chord’s root and mistakenly call it a C chord.

The actual root note is the F on the fourth string.

If you want to make things easier to visualize, simply add a ghost note – the F on the sixth string – which can be found at the first fret.

In both tablature and sheet music, ghost notes are indicated by adding parenthesis on either side of the note.

Omitting (or including) these notes does not impact any of the musical properties of your chord.

It can just be a helpful tool to identify the tonic.

Organizing your Roots and Building Chord Progressions

We now know why chords are given a letter value and are able to quickly identify their root notes.

Once we know the roots of our chords, it’s time to start forming progressions. If you’re a beginner, learning this for the first time, it’s crucial to write your progressions as simply as possible.

My advice is to use your roots to build a raw bass line first.

For example, let’s say we want to write a song in the key of G.

To begin, look up the chords that fall within the key of G major:

Right away we can identify a number of workable progressions, the most obvious of which is G, C and D. Of course, yours could be more complex (different) but, we’ll use this as a simplistic example.

Play through those root notes on your guitar.

Start with a tab like this:

E|-----------B|-----------G|-----------D|-----------A|-----3--5--E|--3--------

The root notes become the foundation of the chord progression you’re going to build.

Now, let’s take a look at some options for making your own creative adjustments:

• Using open chords
• Power chords
• Minor chords
• Adding intervals (seventh chords for example)
• Rearranging the chords
• Introducing new chords into the progression

These adjustments can be made at your discretion.

You’ve done the work of finding a group of chords that you know will work together and you’ve written a bass line that will act as a foundation you can build on.

While there’s no set approach from here on out, try asking yourself the following questions:

There are plenty of different directions you could go when forming a chord progression out of a bass line.

So don’t get so caught up in process that your creative ideas go unimplemented.

How do you “resolve” a chord progression?

In music theory, the term resolve refers to the (somewhat) subjective idea of rest or stability.

More specifically, resolve or “resolution” occurs when a note or chord moves from dissonance (an unstable or tense sound) to consonance (a sound with a stable sense of finality).

Think of how you feel at the end of a song when it sounds “finished.”

That’s what most musicians consider a resolving bass line or chord progression that brings the user to a sense of completion, allowing them to exhale and to know the song (or segment of a song) is over.

It’s a necessary part of both creating and relieving tension within a piece of music.

So, how do we make sure that our chord progression resolves and ends in consonance?

The answer is simple: We go back to our root note.

Fred Sokolow explains the key of a song and resolving, this way:

Let’s say you have a song based on the chord progression we came up with in the key of G, playing through G, C, and D.

For the sake of argument, let’s say the progression goes through the following tab:

E|--------------B|--3--1--3--1--G|--0--0--2--0--D|--0--2--0--2--A|--x--3-----3--E|--3-----------

This is our progression but, it’s not going to sound resolved if we stop on the C. It’ll leave the listener hanging.

Besides, that’s probably not your instinct.

What does your instinct tell you to do?

“Go back to G.”

This is a case where it’s best to listen to your ear and avoid over-thinking the process.

You know that the progression is in the key of G, so make sure to start and finish the segment on the corresponding G chord.

E|-----------------B|--3--1--3--1--3--G|--0--0--2--0--0--D|--0--2--0--2--0--A|--x--3-----3--x--E|--3-----------3--

As a side note, this is often where you’ll have what’s called a “walk-down” where you’ll hear several quick chords that decline into the resolving chord.

In our G, C, and D example, a walk-down to the G might look something like this:

E|--------------B|--1--1--2--3--G|--0--0--2--0--D|--2--x--2--0--A|--3--2--0--x--E|-----------3--

The root notes highlighted in red show the descending pattern ending in the root G.

This is just a chord progression construction strategy that makes the resolving chord that much more explicit and final.

Progressions Based on a Seven Note Scale

So we know that every chord has a root, a key, and we know how to use those two properties to build bass lines which we can turn into a detailed progression.

We even know a little bit about creating tension and resolving those progressions.

However, we can also build our progressions out of a seven-note diatonic guitar scale, basing our arrangement on the seven scale degrees.

Take the C major scale for example:

C – D – E – F – G – A – B

You can easily switch out a different scale, something like the E major if you prefer.

Use of the C major scale is merely to provide a simple example, so feel free to substitute your scale of choice.

In this case, we’re going to extract our root notes for each chord from the progression of notes in the C major scale by identifying and understanding each scale degree.

How to Learn Scale Degrees

The degrees of a scale are descriptors given to each note within that scale, going from left to right – one octave to the next.

Those degrees are as follows:

Tonic – Supertonic – Mediant – Subdominant – Dominant – Submediant – Leading Tone

Thus, C would be your Tonic, D your Supertonic, E the Mediant, and it would continue in that order.

But, how do we get from this to the roman numeral chord progressions we see in websites, books, and other music theory resources?

We’ve all seen them:

What do they mean?

Those roman numerals are assigned to each degree and are used to more briefly and quickly indicate them, as opposed to writing them out. Once we match numerals with scale degrees, we can use the common chord progression diagram to create chord progressions directly from that scale.

How to Use the Chord Progression Diagram

The first thing we need to do is substitute our scale degrees for the proper roman numerals.

So, this…

Tonic – Supertonic – Mediant – Subdominant – Dominant – Submediant – Leading Tone

becomes this:

I – ii – iii – IV – V – vi – vii°

Now we can introduce our circle diagram.

To generate chord progressions, start with the root note, which is the I right before the arrow pointing to ANY.

By following the chart we draw up a progression, step-by-step, that will adhere to the musical leanings of the C major scale.

It involves no guesswork whatsoever.

Here are the steps:

1. Start at I and choose ANY second numeral.
2. I’m going to vi
3. From vi choose either ii or IV
4. I choose IV
5. From IV choose either V or vii°
6. I choose V

V resolves back to I which means our progression is complete.

We have: I – vi – IV – V

If we plug that back into our scale degrees, we get the following root notes for the chords in our progression: C – A – F – G.

So now we have a bass line for our chord progression, we can apply the same creative variances that I mentioned earlier:

• Using open chords
• Power chords
• Minor chords
• Adding intervals (seventh chords for example)
• Rearranging the chords
• Introducing new chords into the progression

Using this system, the line I – vi – IV – V can represent a chord progression in any key that simply adheres to the indicated scale degrees.

It’s an easy way to write chord progressions without actually having to identify the exact chords you’ll want to use.

Instead, we let the diagram do the heavy lifting for us, then we add our own creative touch.

Why This Works

For some, it might seem strange to come up with chord progressions this way.

You might think, “How will I know that it sounds good?”

The reason this works is that chord progressions, especially within a particular genre of music, are almost always highly reused. In other words, there aren’t a lot of them and they typically just get recycled through different songs.

It’s the rhythm and melody that provide most of the variety in music.

So, agonizing over chord progression arrangement isn’t necessary to write a fantastic-sounding piece of music.

We can use theory elements like the chord progression diagram to come up with progressions quickly, giving us to the aspects of music that afford more creative engagement.

Have thoughts or questions?

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Works Cited

Mathematics and Music: Composition, Perception and Performance: by James S. Walker and Gary W. Don | Google Books

GuitarChords.org.uk: guitar-chords.org.uk

Slide Guitar for the Rock Guitarist: by Fred Sokolow | Google Books

Twentieth-Century Music Theory and Practice: by Edward Pearsall | Google Books

Mini Music Guides: Piano Chord Dictionary: by Alfred Music | Google Books

Graphics Courtesy of FreePik.com

Flickr Commons Image Courtesy of Kmeron

Used with the express written permission of Guitar Chalk

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