Easy Diatonic Scale Guitar Lesson Focusing on Theory and Application

For those who are uncertain where to begin studying music theory, diatonic scales are an ideal starting spot.

If you narrow your theoretical scope down to melody and modes (essentially lead guitar), diatonic scale guitar theory becomes a more significant cornerstone. And in this lesson, we’ll explain it.

We’ll also try to make it really easy to understand, by taking a highly complex and mathematical subject, and boiling it down to the information that is most helpful to guitar players.

Benefit of Knowing Diatonic Scale Guitar Theory?

And you might ask, “Why do I need to know diatonic scale theory?”

I suppose you don’t need to.

You can certainly play a lot of guitar without understanding anything about diatonic scales.

But, I also know that some of you want to know what’s going on. And if you’re here, chances are you’re one of those people. So allow me to reinforce your intentions of learning about diatonic scales.

Learning this, and most other music theory topics, is beneficial for the following reasons:

1. Theory teaches you music and not just guitar.
2. The diatonic scale is a foundational pattern that leads into a number of modes you’ll likely run into as a guitar player.
3. Scale-related theory helps you make sense of melodies on the fretboard.
4. All music theory makes you a more serious and respectable musician.

What kind of guitar player doesn’t know how their instrument works?

Sure, you might be able to play really well.

But, isn’t it more significant if you know what’s going on underneath the hood? There’s no better way to truly know your instrument, then in a theoretical sense.

And if you learn it, you’ll be part of a small percentage of guitar players who are working, not just to become impressive guitarists, but accomplished musicians.

Diatonic scales are a great place to begin that journey.

Just the Definition: What is a diatonic scale?

A diatonic scale contains seven notes in succession, with five whole steps (whole tones) and two half steps (semitones), all between two octaves.

Thus:

A diatonic scale in C major would be C, D, E, F, G, A and B, or, all the white keys on a piano going from one C note to the next.

The C major scale, is one of the most basic examples of a diatonic scale.

Here is another example, tabbed in the key of G:

We know this tab is a diatonic scale because we have two semitones and five whole tones within the octave.

Any corresponding transposition of succeeding seven pitches (notes) would also be considered a diatonic scale.

You can also think of a diatonic scale as seven pitches that are ordered on a chain of six perfect fifths. Take the following example, starting at F:

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

Each note is a perfect fifth's distance in front of the note that precedes it.

While there is a lot of additional information and dependencies on diatonic scales, this is perhaps the easiest way to simply define diatonic scales as a concept.

But, what if you wanted to explore some of the more relevant, additional information?

Let’s look at some topics that will shore up our understanding of this concept.

Diatonic Major Scales

The major scale (also called the Ionian mode if its a C major scale), and the minor scale that corresponds to it (natural minor) are both diatonic scale shapes.

From the major scale, you get seven distinct notes and an eighth note that is a duplicate of the root, an octave higher. This is the most common pattern you’ll find that falls under the category of diatonic.

The diatonic scale also includes the following seven modes:

1. Ionian (C major scale)
2. Dorian
3. Phrygian
4. Lydian
5. Mixolydian
6. Aeolian (A minor scale)
7. Locrian

You can see that our major and natural minor scale are both included as Ionian and Aeolian modes.

The more proper terms for major and minor scale - if you don’t use their mode designation - would be diatonic major and diatonic minor.

Because of its relevance, let’s continue to focus on the major scale:

The major scale gives you seven different scale degrees for each note, which include:

1. First: Tonic (root note)
2. Second: Supertonic
3. Third: Mediant
4. Fourth: Subdominant
5. Fifth: Dominant
6. Sixth: Submediant
7. Seventh: Leading Tone
8. Eighth: Tonic (octave)

Each scale degree is separated by an interval, which - when grouped together - create what’s called a sequence of intervals.

Check out the guitar interval cheat sheet here…

And to summarize:

The major scale is the most important and recognizable form of a diatonic scale.

And concerning its construction:

A diatonic scale contains seven notes (and an eighth note which is the octave of the root) with five whole steps and two half steps within the octave.

The Conceptual Versus the Practical

Now, there are two different ways that we need to look at the topic of diatonic scales.

1. Conceptual and Theoretical
2. Practical and Applicable

In short, conceptual is what we understand and know while practical is what we perform or do.

To be a good musician, you need to have both, but you also need to separate them and understand them as two different disciplines.

And you might ask:

How do the two coexist?

Generally speaking, conceptual and theoretical topics should lead us to some kind of application.

In the case of diatonic scales, most of what you’re reading here is theoretical, with distant application. In other words, you don’t really need to think of diatonic scales in terms of how you perform them.

Instead, they’re a conceptual tool that you can use to gain a further understanding of other more directly applicable topics, such as intervals and major scales.

These topics, though theoretical, hold more direct application to what you play on the fretboard.

Diatonic scales help explain and give a definition to these concepts.

Foundational Music Theory

These topics are important because they provide a cornerstone, of sorts, for our understanding of music theory.

As a result, we become more informed and educated guitar players, knowing about music and not just the fretboard.

And if you can be that type of musician, you’ll be in a minority.

This minority, being well-informed, sought-after and highly valuable in studio or performing scenarios, is a good one to be a part of.