So you started playing guitar, it’s going great but you don’t really understand what you’re doing and you’d like to improve your knowledge of music theory. Maybe you’d like to write your own music but you don’t know where to start to express what you feel, or you want to be able to improvise great guitar solos but you have no idea about keys and scales.
Here’s a list of the things you need to check to improve your knowledge in music theory for guitar. The order is recommended in a way that what you learn on the first steps will make it easier to understand the next steps, but you don’t have to stick to it absolutely.
Before diving in, this article is not a full course on music theory. It’s a template of elements required to learn the theory for guitar, so you can make a plan, organize and find resources.
1. Notes on the fret board
The first place to start is a no-brainer. In order to learn about music theory on guitar, it is essential that you know what are the notes on the fretboard. I admit it may seem daunting at first, you may feel that there are as many notes as there are frets on the guitar (over 130). But in reality, you will realize that the cycle starts again at the 12th fret, and the 1st and 6th string have the same notes, that helps diminish the task.
Start with the first 5 frets, notice where the notes start to duplicate on adjacent strings. The guitar has this particularity that you can have the same note on different strings, which is both a blessing and a curse.
2. Intervals
The next step in the learning process is the intervals. At first, it will not seem obvious, but the utility of knowing intervals will come when you’ll learn about scales and chords. The intervals are really important in music, it’s the interval between notes played together, or one after the other, that creates the color in music. In a chord, a change of a semitone for a single note can transform that chord from happy to sad, it’s a powerful concept to master.
Names
The learning process of the intervals for guitar consists of two distinct steps. The first is to learn the names of the intervals. You’ll get numbers, which represent degrees of a scale as you’ll learn with the Major scale, and a quality (perfect, major, minor, diminished, augmented).
On the fret board
The second step, after you learn about all the different intervals, is to see them on the fretboard of the guitar. The goal is to play a random note and then to visualize where are the intervals in the surroundings, within range. For example, the perfect 5th is always located one string higher, two frets higher, from the original note (except between the 2nd and 3rd strings where it’s three frets higher). Some of you may recognize this interval, it’s the commonly used ‘power chord’, which is in fact a single note and its perfect 5th.
Because of the symmetrical nature of the instrument, you’ll notice that you can learn really fast where all the important intervals are. No matter where you are on the fretboard, which key you’re playing, the locations will stay the same. As a matter of fact, you’ll probably know the name of the interval quicker than the name of the note.
And one big advantage over other instruments is that you can play intervals without having to learn the scales for each key. For example, if you play a G on the 6th string, 3rd fret, and you want to add a minor 3rd, you go up one string, down two frets (it will lead to 5th string, 1st fret). If you’re on a piano, wood or brass instruments, you need to think about the G minor scale, the 3rd is a B, but it is flat, so it’s really a Bb.
3. Major scale
This is the most important scale you need to learn, it’s the basis of most of the music you hear on the radio. First, it’s important to understand how the major scale is made before even trying to play it on the guitar. It consists of 7 notes separated by a specific set of whole tones and semitones (W-W-S-W-W-W-S).
Now that you know the intervals, you can identify which one represents each note of the scale in relation to the root note. There will be no surprise with the name of the intervals…
- Perfect unison
- Major 2nd
- Major 3rd
- Perfect 4th
- Perfect 5th
- Major 6th
- Major 7th
Once you know more about the major scale, and you know the difference between C major, G major, and F major, then it’s time to grab your guitar. Most beginners will start with the C major scale on the open position, try to find it on your own as an exercise.
Boxes
But eventually, learning a scale with open strings will keep you limited. You need to learn ‘boxes’ that you can move on the fretboard according to the key you’re in. The goal is to learn the 5 shapes of the CAGED system, after that, you can push a little more by adding two more shapes to reach 7, one for each note of the scale. Learning all 7 shapes, starting with each note of the scale on the 6th string, will help you a lot in the future when you’ll get to other scales and modes.
4. Chords
The next step is learning chords. There’s a good chance you probably know a few chords on the guitar, but it’s good to understand the theory behind them. There are countless chords variations you can play on the guitar, the idea is not to learn them all but to learn how to create them from what you need.
Here are the fundamental elements about chords:
- Triads
- Suspensions
- Extensions
- Inversions / Slash chords
So basically, a chord is a triad (Major, Minor, Diminished, Augmented), then you can suspend the 3rd to either the 2nd or the 4th. After that, you can add extensions (6th, 7th, 9th, 11th, 13th). Finally, you can invert the chord by placing a note that is not the root as the lowest note or put a bass note that isn’t in the initial chord (slash chord).
Chords on guitar
Now you can apply that knowledge on guitar, but there are a few things that are particular to the instrument and are worth mentioning. The guitar has 6 strings (usually), you can play a 3-notes chord using all strings, some of the notes will be repeated at different pitches. For example the common G Major (G – B – D) that most guitar players learn at the beginning, the notes are from low to high: G2-B2-D3-G3-B3-G4. What’s important is that all notes of the chord are played at least once and the lowest note is the root.
Another thing, this time affecting future jazz players. There are chords that have 7 notes in theory, like the 13th chords, there are other chords that would be impossible to play within the range of your fingers if you were to play all notes. In these cases, it’s very common that the guitar player will omit some notes. Usually, the perfect 5th is the first one to go, also the perfect 11th (4th) will rarely be played if there is a major 3rd in the chord.
The last thing about chords, most beginners will start learning chords with open strings first, and later will try barre chords, which is perfectly normal considering the difficulty of the latter. But the power of barre and semi-barre chords is that you can transpose them everywhere on the fretboard, so start learning barre chords as soon as you can.
A few chord shapes to get you started.
5. Arpeggios
Arpeggios are like a mix between scales and chords. There isn’t much more theory behind it that you haven’t learned before, but it’s important to know what it is and what you can do with it. Arpeggios are chords where all notes are played separately. There are two kinds of arpeggios, those where you let each note ring, your left hand isn’t moving from the chord shape and those where you play each note like if you’re playing a scale.
This last kind of arpeggios is the one to put the focus on, it should be treated the same way you learned the major scale. Start with one chord in one position, then learn more positions, then learn more chords. This may take a long time, but since intervals, scales, chords, and arpeggios are all related, the time you put on one element will help you with the others as well.
Guitar arpeggios for beginners
6. Harmonics
Harmonics on the guitar are very interesting, and it’s a great technique to put in your playing. They seem magic and undefinable, but the reality is that it comes from simple physics, let’s not forget that a string that rings is a wave. There are natural harmonics, pinch harmonics, tapped harmonics, but it’s all just the same harmonics achieved in a different way.
Once you understand the harmonics, it’s a good thing to work on pinch harmonics if you plan to play rock/metal music, because it’s part of the language of this kind on guitar playing. They are really hard to explain without having someone show you in person, also you need some gain on your sound and great pickups on your guitar (even the best player will have trouble getting pinch harmonics on a cheap guitar and a cheap amp).
7. Modes and other scales
So at this point, you learned the major scale, but it’s pretty boring to know only one scale. Here’s the surprise, if you learned the major scale all over the fretboard, the 7 positions, one for each note, well you learned 7 modes, and the minor scale as well. The fun thing is that these modes and scales are all built from the diatonic major scale, it’s the same intervals but the root is different. So if you learned to play a C major scale, you can play an A minor scale, or the D Dorian mode, it’s all the same notes. Just remember that each note has a different relation to the root, that’s why they sound different, but the shapes you learned are the same.
To learn more about modes: The mystery about modes in music theory
There are other scales you can add to your knowledge. The pentatonic scales are 5 notes scales based on major or minor scales, they are like ‘lite’ versions of scales.
- Pentatonic major
- Pentatonic minor
- Harmonic minor
- Melodic minor
- Blues scale
8. Melody and harmony
If you want to analyze music, or write songs, the concept of melody and harmony is very important. One way to visualize this is thinking of the melody as being the succession of notes (horizontal) and the harmony being some notes played together (vertical).
What makes the music sound a certain way is an interaction between many elements. The melody notes are related to the chord played on the harmony, the melody notes are also related to each other, the movement they make, the interval they use. The chords are also related to each other. All the notes and chords played are within a scale, which is related to a root…
That’s a lot of information, let’s visualize this like this:
- The root note is the leader
- The leader chooses other notes to form a scale, a template of notes to work with it
- Some notes form groups to create chords
- Some other notes decide to work solo but get associated with groups, this is harmony
- Over time the associations change, this is melody
From a guitar perspective, there are situations where the instrument must focus on the harmony and others where it’s melody. For example, if you’re a singer with an acoustic guitar, the melody will be your voice, and the guitar will serve as an accompaniment, the harmony part. But if you’re playing a solo in a rock band, you’re the melody and the rest of the band provides the harmony.
9. The ‘rules’ in theory
Here’s another concept that can give a lot of confusion to musicians, the rules of music theory. I see a lot of questions like: ‘Can I play that chord in that chord progression?’ or ‘Can I play this note that is not in the key?’. The truth to these questions is always the same: ‘Yes, why not?’.
There are some rules in music theory, for example, the C major scale is C-D-E-F-G-A-B, it follows the rule of the intervals of the major scale. But that doesn’t mean that it’s impossible to play an F# in a song in the key of C major. If you break these rules, you’re not doing anything wrong, but you’re creating an effect. And if this effect is desirable or not, it’s all a matter of the listener.
An analogy to that concept, think of music as a meal. If you play something simple, always staying in the key, always using notes in the melody that follows the chords in the harmony, you’re mean will taste good but very plain. If you start adding notes or chords that don’t belong to the key, it’s like you’re adding spice to a meal. Some people prefer more spice, some less spice, some real freaks will want an amount of spice that most of the people would not stand.
So the real rule in music theory is, does it sound good for you?
10. Improvisation
Most of the guitar players will come to a point where they need to improvise. This is a culmination of all the points we’ve seen so far, everything you learned about theory will come into play in improvisation. The way to dive into this is the same way you would do while learning a new language. You start by learning a few rules, a few words, a few sentences, and then you need to put it all together in a way that the listener will understand.
The only way to improve improvisation is practice. Play over songs you listen to at home, jam with other musicians, listen to yourself and try to improve what you don’t like. It takes time, and there is always an improvement to make, but it’s really fun to do.
Other resources
- https://www.musictheory.net/
- https://www.justinguitar.com/
- https://guitar.com/
- https://www.guitarlessons.com/
