Holistic Overview Of ALL Guitar Music Theory

I want to learn music theory, but where do I start?

Luckily, I have broken down ALL the areas of music into NINE categories. So that you can evaluate what you do know, what you don’t know, and more importantly what you NEED to know!

What are the key areas of guitar music theory? The key areas of guitar music theory can be broken down into ELEVEN learning segments. These include:

  1. Intervals
  2. Musical Keys (Relative Keys)
  3. Musical Alphabet
  4. The Major Scale
  5. The Natural Minor Scale
  6. Pentatonic Scale
  7. Blues Scale
  8. The Harmonic Minor Scale
  9. The Melodic Minor Scale
  10. Modes
  11. Arpeggios
  12. Chords

The purpose of this article is to get an idea of everything that is involved in music theory before you go out and learn it. We explain what each part of the music theory is. However, you will need to visit our other posts to really get a true grasp of how to apply each of these in your actual playing the guitar.

1. Intervals

Intervals, perhaps the most frequent encounter in music theory learning, and is very intimidating for beginners. Luckily, it is not difficult to understand.

Why are intervals important?

Before, I teach you how to understand what intervals are let’s first understand their importance.

Intervals are important in the sense that they are the foundation of music theory. Chords, scales & arpeggios share the same patterns and shapes. This means you only need to learn chords, scales, and arpeggios once and then you can move them across the fretboard to form other scales.

Because of intervals, you form your music theory knowledge on bases on patterns or shapes rather than learn each note for every key you are playing. Even better, you only need to memorize one scale (being the major scale) as ALL other scales use the exact same shape or pattern.

Simply put, because of intervals, as we move the chords and scales to different keys, the notes within the key still change but the shapes or patterns do not change because the intervals do not change.

What Are Intervals & How Do They Work?

The interval implies the patterns in musical scales, chords, and arpeggios. Moreover, intervals are simply the spaces between the notes. In other words, when we talk about the patterns of scales and chords, we are actually referring to the intervals between the notes of these scales and chords.

In the simplest term, intervals refer to differences or gaps in tone between two pitches, or notes.

The difficulty for beginners is usually distinguishing the notes and their differences. To better demonstrate the intervals in action, guitarists can use the fretboard as a guideline.

If your guitar is in standard tuning (EADGBE) and you place your index finger on the 1st fret of the 6th string (low E string) you will get an F note. If you again place your index finger on the 3rd fret of the same string you will play a G note.

This is an interval of TWO.

Whole Tones & Half Tones?

As discussed the difference between F and G is two frets (F# and G) meaning there is an interval of two.

Intervals are presented by wholes and halves. From F to F# is a halftone and from F to G is a full tone. One halftone is one fret and one whole makes 2 halves being two frets.

Music theorists can refer to a Whole tone as Fulltone or a Tone. Whilst they may refer to Halftones as Semi-Tones.

2. Musical Keys

We will let you in on a secret of lead guitarists: Lead players do not just feel the notes, experiment and improvise as they play, rather, they follow a responding musical key and play the notes from the scales that match the key.

What are Keys?

Keys, in essence, are a collection of notes that when played together, will sound good – in a fancier word: Harmony.

If we just play the notes randomly on the go, high chances are they will sound clunky, out of place. This is because they do not belong in the same key. In layman’s terms, notes in the same key will sound pleasing to the ear.

As music has progressed over the centuries, music theorists have discovered that there are just 12 keys.

These 12 keys include: C C# D D# E F F# G G# A A# B

IMPORTANT: The hashtag symbol # indicates a sharp note which is an entirely separate note.

Keys to Learn

Pop music can be played in any key and there is not an absolute rule. As each key will vary slightly in pitch will make it harder or easier for a singer to match their vocal range, and so the key is usually chosen by who is singing.

Because of this principle of how intervals and keys work together, guitarists do not need to learn all the notes and chords in a key. You only need to learn 1 and then this can be transposed anywhere across the fretboard moving seamlessly between scales and keys.

However, that being said the most common keys people play in usually depends on two things. It can be the style of music that you are playing or the vocal range of your singer.

If you are playing rock then E minor is the popular key to starting learning. Also, blues players will usually play in A minor.

However, there is no rule. For example, the band ACDC is a good example of a rock band that plays in A minor due to their blues influences.

3. The Musical Alphabet

Along with sharp notes (#), which indicate half a step higher in key, there are also flat notes (b). Contrary to sharp notes, flat notes are used to demonstrate half a step lower than the notes they represent. For this reason, flat and sharp notes are fundamentally the same. For example, and A# can also be referred to as Bb. And because there are no B# and E#, Cb and Fb also do not exist.

The main difference between flat and sharp notes lies in how they are used. As sharp notes indicate higher key while flat notes represent the lower key, musicians use them to present the flow of notes, for ascent (A to G), they will use sharp notes while for descent (G to A), flat notes are preferred.

Relative keys

Relative keys are keys that share the same notes and chords.

For example, the notes in the scale of C major scale are CDEFGABC (with no sharps or flats). Then we have the A minor scale, whose notes are also ABCDEFGA. Even though they have different starting and ending points, the notes are exactly the same. The only thing that has changed is the starting point of the scale (or known as the Root Note).

It may not be obvious right now as I’m only providing a simple description. But, even though the intervals have changed between the patterns between the Major and Natural Minor is exactly the same as the A natural minor scale belongs to the same family as the C major scale.

Okay, so I know this is a little confusing right now but it will make sense when we look into the Major scale below. Alternatively, the only thing you need to take away here is that there are 6 relative keys within each key.


So it may be confusing that I mentioned earlier that each key only contains 6 notes. The question I was asking here was, “but guitar players are playing many different sounding notes”

This is because of octaves.

An octave is the same note, but with higher or lower frequency.

For example, the note C can be played in many places on the fretboard. Depending on where you play it, Notes C will always sound different. However, if you compare the low or high version you will always hear it is the same note. It is just the pitch that has changed.

4. The Major Scale

The major scale is the BEST starting point for putting music theory into practice.

This scale encompasses other more complicated scales you will learn in the future. As such, it is crucial to understand deeply this scale. To demonstrate the theory of the major scale, we will use the key of C Major.

In C major scale, there are no sharps or flats and the 7 notes go from C to B. Guitar theory will usually use roman numbers to present the notes in a scale (illustrated below).

C Major Scale Wth Intervals 2

The first note of the major scale is always the root note of the scale, in this case, a C. After that, a major 2nd, major 3rd, perfect 4th, perfect 5th, major 6th, and major 7th.

To easier understand the intervals in a scale, it’s better to remember the number representing the halves. In the case of C major scale, the pattern is 2 2 1 2 2 2 1, which means, the root note is 2 frets apart from the major 2nd, and major 2nd is 2 frets to the major 3rd, and so on.

Applying these numbers to the frets of the guitar will form a pattern, which we usually refer to as the major scale.

5. The Natural Minor Scale

Now that we are clear about the major scale, the minor scale should be a walk in the park.

Same as the major scale, the minor scale also consists of seven notes. To better demonstrate the intervals of the scale, we will use the A minor scale. The A minor scale starts with an A and ends with a G, no flat or sharp notes.

The pattern of the intervals in the minor scale is very similar to that of the major scale, beginners should remember it as 2 1 2 2 1 2 2. Which means, the first note is 2 frets away from the 2nd and the 2nd is 1 fret away from the 3rd note and so on. In the case of A minor scale, the scale starts with an A, move two frets forward we will have a B, 1 more fret is a C and then end with the G.

As beginners may have problems recalling the name and the location of the notes on the fretboard, we recommend playing by this pattern to get used to the tone and to form other minor scales. To form other scales from this pattern, simply change the starting note and apply the pattern from there. Keep in mind that intervals are always the same across all minor scales. Both the major scale and the minor scale are the foundation of the guitar scale, the only two tonalities in music: major and its inverse version – minor.

6. The Pentatonic Scale

Pentatonic Scale comes in the form of both major and minor pentatonic.

Pentatonic Major Scale

Pentatonic Major Scale is essentially a simplified version of the full major scale where a few notes are taken away. A Pentatonic Major Scale is thus easier and friendlier to starters.

Pentatonic Minor Scale

Similar to its major counterpart, minor pentatonic scale is the minor scale with a few notes removed. Minor pentatonic scale is definitely one the simplest scale pattern and arguably the best scale to start learning. In fact, many guitar teachers use the minor scale and the pentatonic minor scale as introduction to this music theory instead of the major scale.

7. The Blues Scale

The Blues scale is one of the easier scale to master, and thus, more than often, recommended for beginners to practice. The pattern of this scale is also very similar to the pentatonic minor scale, making it an effective follow-up practice in case you have mastered the pentatonic minor scale.

To play the blues scale, you just need to add one note from the pentatonic minor scale only. And rest assured that this one note does make all the difference. Despite the name, Blues scale is very versatile and is often used by artists of other genres and settings as well. It is very easy and fun to use. For beginners and novice players, experimenting with this scale or using it to practice finger movements are all very good ideas.

8. The Harmonic Minor Scale

The harmonic minor scale, my personal favorite.

It is definitely the must-know scale for anyone that wants to learn guitar.

Surely, it is not as easy as the pentatonic scales but with time and patience, anyone can master it. Below is the illustration of the A harmonic minor scale. Similar to major and minor scale, the harmonic minor scale, too, has seven notes.

For the A harmonic minor scale above starts with the 5th fret on the 6th string and ends the first octave at 6th fret of the 4th string, after that you will see the same notes repeat but an active higher.

Do keep in mind that this is just the pattern for the scale and like all scale pattern, this one is movable so that you can playing this same shape in different Keys. For example, if you want to play the G harmonic minor scale, simply move the root note to the 3rd fret of the 6th string and start applying the pattern there.

Intervals of the Harmonic Minor Scale

Intervals are crucial knowledge in learning guitar, or any musical instrument for that matter. They are the basis for scale theories and will greatly improve your knowledge and understanding of the fretboard as well as how to transform said theories into practice.

The harmonic minor scale starts with the root note, major 2nd, major 3rd, perfect 4th, perfect 5th, flattened 6th and major 7th, as shown in the picture.

In addition, same as the scale patterns, the notes will change with the key of the scale but the intervals would remain the same regardless of what key you are playing in.

Chords of the Harmonic Minor Scale

Like intervals, notes and chords are basic knowledge in understanding of the scales. Essentially, guitar scales contain root notes, which can be used to form guitar chords. In the image below, we demonstrate the root notes and their corresponding chords of the C harmonic minor scale.

The harmonic minor scale starts with the Minor 1st, Diminished 2nd, Augmented 3rd, Minor 4th, Major 5th, Major 6th and Diminished 7th, as shown in the picture above.

For instance, the first note of the scale is a minor and a C, as such, we can form a C minor chord there. Similarly, we can D diminished, or E flat Augmented and so on. Do keep in mind that the scale patterns are movable and so are the chords. The first note of the G harmonic minor scale can be used to form a G minor chord just like that.

9. The Melodic Minor Scale

As a minor scale, the melodic minor scale does sound mysterious yet also a bit uplifting. This scale is frequently used in jazz music. Due to the distinctive mood of the scale, artists can build up tension and release to the song.

This scale is the same as the previous harmonic minor scale except for one note. For this reason, if you master the harmonic minor scale, the melodic minor scale should be a walk in the park. The pattern of the melodic minor scale is as presented below, in the form of A melodic minor scale. And like the harmonic minor scale before it, this scale starts with the 5th fret of the 6th string and ends at 6th fret of the 4th string, concluding an octave. Do keep in mind that this pattern is movable across the fretboard, and can be used to form other scales starting with the root notes.

Intervals of the Melodic Minor Scale

The formula of the melodic minor scale is as presented below. Starting with the root note, then a major 2nd, major 3rd, perfect 4th, perfect 5th, major 6th, and major 7th.

Essentially, this scale is the harmonic minor scale replacing the flattened 6th with a major 6th.

Chords of the Melodic Minor Scale

From the melodic minor scales, you can use the notes to form the chords, just like the harmonic minor scale. However, the chords for this scale are drastically different.

Using the C Melodic Minor chords, we can have a C minor, D minor, Eb Augmented, F Major, A Diminished, and B Diminished. Take note that the progression of these chords are applicable to other melodic minor chords as well.

10. Modes

Modes is another very important topic as it highlights all the different sounds you can hear in the major scale,  harmonic minor scale and melodic minor scale.

Modes are essentially scales. But, more specifically they are the different characteristics, modes, or moods that the scales are capable of voicing.

There are six modes to every each of these scales making 18 modes in total. It is also important to highlight that the natural minor scale, is actually also found as a mode that belongs to the major scale.

Modes are grouped in families and the root of the scale can be considered the parent whilst the other can be considered a child. Each mode belongs to either major or minor which basically means a happy sound or a sad sound. Please see below…

Major Scale Modes

So, first, let’s look at the modes of the major scale. Starting with the C major scale (C D E F G A B).

C Ionian mode

C Ionian MODE is the first mode of the C major scale is  C D E F G A B C. This is a major sound, which as you may notice is what we have also described as the C major scales. Simply enough C Major and C Ionian are identified as being the same thing.

however, it is important to note there is a difference. Because when you refer to C major you are referring to the scale that encapsulates all the modes. Where, when referring to Ionian you are only referring to the first mode.

D Dorian Mode

D Dorian MODE  is the second mode of the C major scale and it is D E F G A B C D. This is a minor sound and the difference that the root note has become the second note in the scale with preceding notes still following in ascending order from the major scale.

It is a minor sound as the root chord of this mode is a minor (D minor).

E Phrygian Mode

E Phrygian MODE is the third mode of the C major scale and it is E F G A B C D. This is another minor sounding voicing where the root note is E minor.

F Lydian Mode

F Lydian Mode is the fourth mode of the C major scale and it is F G A B C D E. This is a major voicing with the root note being R major and is an uplifting sound.

G Mixolydian Mode

G Mixolydian is the fifth mode of the C major scale and it is G A B C D E F. This is a major/minor sound as the root chord is dominant. You can bring a combination of happy and sad as dominant chords contain the keynotes of both major and minor with a unique sound that’s different from the other modes.

This mode is commonly used in jazz. However, it is very versatile and doesn’t always sound jazzy it depends on how to want to phrase it and the type of chords you use.

A Aeolian Mode

A Aeolian Mode, also known as the natural minor is the sixth mode of the C major scale being A B C D E F G and it is a minor sound with the root note is A minor.

B Locrian Mode

B Locrian is the sixth mode of the C major scale and it is B C D E F G A. This starts with the B minor root chord and sounds very evil. This is rarely used in pop music and is also known as the half-diminished.

Major Scale Keys and Modes

Harmonic Minor Scale Modes

C Harmonic Minor

D Locrian #6

E flat Ionian #5

F Dorian #4

G Prygian #3

A flat Lydian #2

B Super Locrian

Melodic Minor Scale Modes

11. Arpeggios

12. Chords

As keys are collections of chords that work well together, chords in a key come from notes of that scale for that key.

Major Scale Chords

As in the key C Major, the chords of key come from the notes of the key itself. In other words, we can think the scale and key are the same thing and lots of musicians use the terms interchangeably.

For major scale, there are three major chords, three minor and one diminished chords, seven chords for seven notes in the scale. The major chords are I, IV and V, or, in the case of C major, are the C, F and G chords respectively. The minor chords are II, III and VI, or the D minor, E minor, and A minor for the scale of C major. The remaining VII is the diminished chord, or B diminished.

As we can work out from the connection of the chords and notes, the notes of the scale will become the chords of the key. Knowing the chords of a key will allow for structures in your playing as you now know what chords will go well or harmonise with the other

The “key” takeaway here is chords and keys come from the notes from the scale that matches that key. Having this simple knowledge and you will find the interaction between the notes in a scale much more fascinating.

Minor Scale Chords

Consisting of seven notes, the minor scale also consists of seven responding chords, the minor chords, major chords and a diminished chord, similar to the major scale. Obviously, a minor scale will start with a minor chord, in the case of the A minor scale, this is the A minor chord. Other two minor chords are the IV and V, respectively D minor and E minor in the A minor scale. the major chords are the III, VI and VII, which are the C major, F major and G major in the A minor scale. Lastly, is the diminished chord – II, the B diminished.

Once again, learn and practice this scale thoroughly before moving on to other more advanced theories. With an understanding of the chords in the minor scale, you will know the relevant chords to pair with each other and effectively find the key of a song you wish to play.


Guitarists don’t like to learn letters, we get it. Guitarists like sound, the very thing that inspires the essence of the soul, like feeling the melody inside and hearing it manifest in reality.

Little did we know we have put the cart before the horse.  Creating an inspiring tune and playing the guitar in front of a crowd, these are only daydreams if the core of music is not mastered. The prerequisite of playing music is always learning about music. No matter how we try to steer away from the theories and jump right into the strings, we soon find ourselves unsatisfied and to a definite extent, our progress suddenly comes to a halt.

Firstly, familiarize yourself with the basics and try to experiment with it. After that, we may find that theory is not really boring at all, in contrast, it is actually fun and practical. Only the idea of learning is boring, the process itself is not. And once you get the gist of it, you will certainly understand the connection in music, as to why certain notes go well with each other while the other is an abomination. But, like learning all other things, always couple your newly acquired knowledge with regular practice, too much theory can be very overwhelming and possibly stunt your growth as a musician. This is why we encourage picking up new theory in manageable chunks and trying to master them before moving on to more complicated theory.

Upon learning, you will find a lot of theory will not make sense and will contradict each other. Don’t be discouraged and rest assured that this is a phase everyone will go through. As you continue to learn, the pieces will naturally gather without you ever realizing it.
In this article we will be looking at the following:

With that said, the feel, tone, and progression of the notes will be different, because, after all, they are different keys and we are playing them in different orders. This is the effect of intervals; the feel of the music depends heavily on how each note relates to the note right after.

Knowing this will help you immensely in picking up guitar scales and transform one scale into another. Since for one scale, there will be another scale with the exact same note, which enables you to replace the scale. Your learning progress therefore should be twice as fast knowing this. For example, you need to transform a major scale into a minor, simply move up 3 frets as the minor scale is always tonally lower than the major scale. Doing this and you can play any song just with the easy pentatonic minor scale. You can perceive a scale as minor but what you play is actually major.


Rich Wilde Music

My name is Richard Wilde and go by @richwildemusic on all major social channels. I am an artist, guitar player, and producer. I have been playing guitar for over 15 years and have come to learn the "tips" and "tricks" to enhance guitar playing, recording guitar, setting up guitar, and overall get that professional sound.

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