A Straightforward Guide to Guitar Music Theory for Songwriters and Singers

While a lot of this content fits together, I think it’s better learned in segments so you can retain as much as possible. Remember, I’m not trying to make you into a theory expert. I’m simply covering the aspects of music theory that are relevant to your guitar playing and songwriting.

Take your time and really understand what you’re learning.

Section 1: How to “Know What You’re Playing”

This can be one of the single biggest frustrations for those who know some guitar, but little or nothing about what they’re actually playing.

Typically, you can strum and chord well enough, yet have no real idea of how it all fits together.

In all likelihood, this is what you’ve done as you learned the instrument:

You’ve memorized patterns and repeated what you’ve seen other people doing.

Now, it should first be pointed out that this isn’t a bad thing.

In fact, memorization and simply doing what we see other people doing on the guitar are both valid methods of learning.

The problem is that we often fail to supplement those tactics with our own understanding of what we’re actually playing.

We never take the time to look under the hood of the car we’re driving.

What the diagram demonstrates, is that you can know what you’re playing simply by knowing the key and being aware of the scale that your chord progression fits into.

It all will connect.

This construct is a particularly helpful way for songwriters to look at their chords, since they’re often using common chord progressions based on a key and scale, whether or not they realize it.

Here are a few resources where you can look up scales and chord progressions for different keys:

• Chords in the Key of C
• Chords in the Key of E
• E major Scale
• C major Scale
• D major scale

In short, you could say that you’re playing chords, in a progression, based on a scale that comes from a key. We’ll get into all of this more as we progress through the other topics.

Section 2: Root Notes and Memorizing the Fretboard

While memorizing the guitar fretboard isn’t the most exciting discipline, it doesn’t take as long as you might think. Furthermore, once you’ve gone through the trouble of memorizing it, the patterns stick with you and don’t have to be re-memorized.

First, let’s get familiar with the theory involved.

What is a root note?

We learn the fretboard notes so we can identify root notes.

If you don’t know what a root note is, think of it as the note that gives a chord its letter value.

Thus, the G major chord is a “G chord” because of the root G note.

Once you know where the G notes exist on the fretboard, you can then easily identify (or build) G chords in those spots.

The root note is almost always the bass note of the chord or the lowest note in the grouping.

Ottó Károlyi, a senior lecturer at the University of Stirling in Scotland, is credited with informally expanding the definition of a chord to include two or more notes, as opposed to the more widely accepted definition of three or more.

For our purposes, this is simply extra credit and a worthy side-note.

The more important part of the definition to understand is that a chord is any grouping of notes sounded simultaneously, or at least side-by-side, as in the case of an arpeggio (chord picked one note at a time).

But what about composition?

What is a chord made up of?

Parts of a Chord

The parts of a chord can be broken down into two different segments:

1. Root note
2. Intervals

First, you establish your root note and then build the rest of the chord based on that root.

A root note is sort of like the nucleus of your chord.

Intervals are all the notes in a chord that correspond to a chord’s root.

Take this power chord, for example:

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

We can see that the root note is positioned at the third fret on the sixth string (the low E string), which means the other two notes are intervals of that low G.

Intervals are simply ways to designate the distance between two notes.

Here’s an interval cheat sheet, if you want a quick reference and memory aid.

For more background info on intervals, you can checkout our post, Guitar Intervals Explained.

For now, I’ll just give you the intervals for each note in the chord from the previous tab:

• 5th
• Octave

The first note (fifth string and fifth fret) is a fifth or “perfect fifth” interval.

The second is an octave up from the root, meaning they’re both G notes.

For any chord, you can figure out the intervals of each note by simply counting the distance in frets between that note and the chord’s root.

Let’s start with something really easy.

We’ll bring back our G major scale:

G, A, B, C, D, E, and F♯

Start by picking the low G note on the third fret with your thumb and then plucking the open G and B string like this:

E|--------
B|-----3--
G|-----0--
D|--------
A|--------
E|--3-----

From there, we can move the root note to F♯, A , B and C quite easily:

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

Now, this pattern won’t necessarily challenge you, but it should allow you to more clearly see what’s happening when you move the root notes around in a fingerpicking pattern.

The root notes change while the intervals stay the same.

As long as the root notes are all a member of the same scale (in this case, the G major scale), it will sound consistent and will resolve without too much tension.

Understanding Time Signatures: 4/4 Time

I’m throwing time signatures in with the fingerpicking section because of how directly applicable it is to the technique.

Before we get into specific time signatures and how they manifest in acoustic fingerpicking, let’s try and understand the concept broadly.

First, the term “time signature” is a notational convention used in sheet music.

You can spot them directly after the treble clef:

What do these two numbers mean?

• The lower number represents the note value or what type of note (quarter, half, etc.) is being played in the bar.
• The higher note tells us how many of those beats will occur within a single bar.

For example, the most common time signature, 4/4, can be understood as four quarter notes.

Additionally, 3/4 as three quarter notes, 3/8 as three eighth notes and so on in the same manner.

In most cases, a time signature is maintained throughout a song.

All this means is that to fingerpick in 4/4 time, we would be picking four quarter notes per measure, like this:

Here’s how I would attack this arpeggio:

1. Play the root note with your thumb
2. The two open notes with your index and middle finger
3. Then the high interval with your ring finger

By far, 4/4 is the most common time signature.

In fact, you’ve probably spent most of your time playing in it, whether you realized it or not.

That said, there’s another common time signature that’s worth taking a look at.

Fingerpicking in Time: 3/4

This means we’ll be playing three quarter notes per measure, which will give off a kind of waltz feel and rhythm.

Let’s use the same C chord since it’s an easy pattern to remember.

We’ve included three quarter notes (the last two are chorded) in the bar:

From here, we can plot our fingerpicking pattern in a similar manner:

1. Thumb plays the root note
2. Index plays the first interval (on the second fret)
3. Middle and ring grab the last two chorded notes

Combining Root Notes with Dyads and Triads

To finish up the theory behind fingerpicking, I’ll show you how to combine root notes with dyadic and triadic chord shapes.

We’ve already shown that in fingerpicking it’s common for the root note of a chord to change while the higher intervals stay the same. For this concept, we’ll separate the root notes from the intervals again but, this time we’ll be more specific about how we group the intervals.

When you’re fingerpicking through a root note/interval pattern, you have essentially three different ways you can group those higher intervals together:

1. As single notes
2. Dyads (groups of two)
3. Triads (groups of three)

Now, be aware, the formal definition of a triad is a chord that is stacked in third intervals.

You don’t have to worry about that here, because the term “triad” can also be used to describe any grouping of three notes that resolve with the root.

Just be aware that a more focused definition exists.

Let’s start with dyads.

Here’s an example where we’ve broken an E chord up between the root note and three other dyadic groupings, played in 4/4 time:

If you were to break the shape up by triadic grouping, it might look like this:

Again, you can change your root note while using the same combination(s) of intervals.

How you arrange them is up to you. Just make sure you have a handle on how these notes correlate with the bass line and give structure to your fingerpicking:

Section 5: The Guts of Chord Progressions

Incidentally, we’ve already covered a lot of what would be considered chord progression theory.

Without being redundant, I want to reinforce some of these ideas while also taking a closer look at some of the most common chord progressions you’re likely to use as a songwriter.

So, let’s briefly review what we already know:

• Chord progressions always have a key.
• Chord progressions are therefore based on a scale within that key.
• These scales give way to commonly used chord progressions.

Also, note that chord progressions drawn directly from a scale will share the numeral of their corresponding scale degrees, giving you progressions written like this:

I - IV - V

Assuming you’re in the key of G, this would indicate a G, C and D progression since G, C and D are the first, fourth and fifth degrees in that scale.

You could then take that sequence of numerals and apply it to any scale, thereby giving you a workable progression directly from that scale.

Now, that doesn’t mean that you must write chord progressions this way.

I still write them out without the numerals, in favor of their letter note values.

At the same time, it’s helpful to know how to use the numerals of scale degrees to easily move chord progressions from one key to another and to know what they are when you see them. Because that’s essentially what a chord progression is; a collection of scale degrees.

From here, let’s move into a closer look of some specific chord progressions.

Focusing on the G, C, and D Progression

One of the most common chord progressions is G, C, and D.

While the order can change, we know now that we’re working in the key of G with the first, fourth, and fifth scale degrees: I - IV - V.

Let’s take a look at the root notes we’re utilizing:

E|-----------
B|-----------
G|-----------
D|--------0--
A|-----3-----
E|--3--------

We have our low G and C, positioned on the sixth and fifth strings respectively, while our root D note is the open fourth string.

If we fill out the chords, the tab usually looks something like this:

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

Now, based on our root notes, what else can we do with this progression?

In an article I wrote for Guitar World, I covered how to mod this progression and sort of “clean it up” a bit.

I kept the root notes and didn’t add any minor intervals.

Here’s what I came up with:

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

Basically, we minimize the chord and set it up so that all we have to do is move the root note from G to C and then the open D.

It makes the progression much easier.

I would also contend that it sounds better.

It has a nice, consistent ring when arpeggiated and also makes for a clean strumming tone without unwanted pick scraping.

But, what if we wanted to barre the shape or use power chords?

The same theory applies.

Start with the same G and C root notes, then move the D root to the fifth fret on the fifth string:

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

Now, we can add our perfect fifth interval to create power chords:

E|-----------
B|-----------
G|-----------
D|-----5--7--
A|--5--3--5--
E|--3--------

If you want to create a progression of barre chords, we’ll need to add at least two more intervals.

Here, we add the octave and major third to each chord:

E|-----------
B|-----5--7--
G|--4--5--7--
D|--5--5--7--
A|--5--3--5--
E|--3--------

There are a lot of different ways to handle the G, C, and D progression, so I’d recommend figuring out which one works best for you.

And that’s not to say that there’s anything wrong with the formal “chord book versions,” but just know that there are a number of ways to handle any one grouping of chords.

Focusing on the E, A and B Progression

If we take our scale sequence (I - IV - V) and move it from the key of G to the key of E we get another common progression that you’ve likely used quite a bit; E, A and B

We’ll run through at a few different ways to play it and handle the root notes.

Let’s first look at the formal, open version:

E|--0--0--0--
B|--0--2--0--
G|--1--2--4--
D|--2--2--4--
A|--2--0--2--
E|--0--------

My only suggestion here is to omit the last interval on the second fret for the A chord, which allows you to play the progression more open:

E|--0--0--0--
B|--0--0--0--
G|--1--2--4--
D|--2--2--4--
A|--2--0--2--
E|--0--------

If you want to build the power version of this progression, simply omit the lower notes from each chord until you have only the root and 5th of the chord remaining:

E|-----------
B|-----------
G|-----------
D|-----2--4--
A|--2--0--2--
E|--0--------

Another super easy way to play this progression is to move the power chord shape to a position at the seventh fret:

E|-----------
B|-----------
G|-----------
D|-----7--9--
A|--7--0--7--
E|--0--------

Just as in our other examples, we can continue adding intervals that thicken the harmony of the chord:

E|-----------
B|-----------
G|-----6--9--
D|--9--7--9--
A|--7--0--7--
E|--0--------

Note that the E, A, and B progression is more structurally suited for power and barre chord progressions than an open arrangement, though it can be effectively used for either.

6. Scales for Songwriters

What do songwriters need to know about scales?

Should you know a lot of them by heart or have them memorized?

Which ones matter the most?

We’ve talked a lot about scales already and have even seen how scales (the major scale) can give us a framework for chord progressions and playing in a key.

If you understand the more conceptual side of scales, it will serve you better than if you just memorize a handful of them and don’t really know what they mean.

So first, let’s try and solidify our understanding of guitar scale music theory before we attempt any memorization.

What is a scale?

A scale is a sequence of notes that is ordered by pitch.

For example, the C major scale includes the following notes:

C - D - E - F - G - A - B

On the guitar, you could tab it out like this:

E|--------------------------
B|--------------------------
G|-----------------2--4--5--
D|--------2--3--5-----------
A|--3--5--------------------
E|--------------------------

That last note (at the fifth fret) is a C, an octave higher from the root C that begins the sequence on the third fret. At that point, the seven note sequence simply repeats.

On a scale diagram, you’d write the pattern this way:

Theoretically, this shape can repeat itself anywhere on the fretboard where a C note exists, since the sequence of notes doesn't change.

What does it mean?

Now that we’ve seen a scale and plotted the notes, what does it mean? What implications does it have for our guitar playing and songwriting?

Primarily, a scale provides a grid for two important musical components:

1. Melody
2. Harmony

When you sing a melody or harmony with your voice, you’re almost always utilizing a group of notes from within a particular scale or melding a few different scales together.

It’s no different with your guitar.

And notes that resolve together in a given key are always going to share a common scale or collection of modes (variations of a given scale).

In other words, harmony and melody are governed by scales and modes.

How to Use Scales as a Reference

To that end, scales can be useful for the following purposes:

1. Developing chord progressions
2. Identifying notes within a key
3. Identifying chords within a key
4. Building lead melodies and harmonies to cover chord progressions
5. Creating resolve (an auditory feeling of relaxation) or tension (creating a need to feel relaxed or “released” from a note)

Scales can be used as a reference point for all these things.

For example, let’s say you know you’re playing in the key of G and you want to develop a new chord progression in that key.

We’ve already seen how we could use the G major scale to cobble together chords that already exist within that key.

Further, we can use that same scale to build lead sequences and melodies to go over those same chords.

They’re the skeleton and backbone that holds music together.

Do I need to memorize scales and modes?

My personal opinion is that it’s not necessary to memorize a lot of scales as they are.

Why?

Because you won’t ever really need to play them straight through, at least not as a songwriter.

…most songwriters, who lean more on chords and the acoustic style, do not need to spend a lot of time memorizing scales.

Now, just because it’s not necessary doesn’t mean it’s not beneficial.

Music students make a regular practice of memorizing scales and modes, even to the point of being able to identify them as they play and switch between them.

What you need to decide is whether you want to use scales directly, in that same manner, or if you’re simply going to use them as a theoretical tool.

My conclusion is that most songwriters, who lean more on chords and the acoustic style, do not need to spend a lot of time memorizing scales.

7. Why the Major Scale is your Best Friend

In fact, my advice would be to narrow your focus and get well-acquainted with the major scale in the keys that you most commonly play in.

Most of the progressions you play will have their roots in a basic major scale, which you can then use as a reference point for vocal melodies, harmonies, guitars solos or piano-based melodies.

The major scale is a structural component that shows up all the time. So, if you memorize any scales at all, I’d recommend that it be a major scale in the key of C.

Once you get comfortable with that, move onto a couple other keys and memorize the scale in those keys as well.

Where should I plot the major scale on the fretboard?

I would start by trying to keep scale forms close to where you play most of your chords.

For example, if you play a lot of open chords with root notes on the second and third frets (most songwriters do), you should use the second and third fret form of the major scale.

You can actually look up each scale form if you’re not sure what the notes are.

Keeping Fingers Close to the Fretboard

What I want to tackle now is one of the more practical and concrete problems that acoustic guitar players, and those who don't consider the guitar their primary instrument, tend to run into.

Simply put, it can be hard to keep your fingers on the fretboard.

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