Guitar Harmonics: How Do They Work? How to Make Them Louder & Much More!

However, we must first know that when we speak of harmonics we always refer to waves that propagate through a medium. In the example of guitar harmonics we’re talking about sound: Sound is made out of mechanical waves transmitted through the air.

And second, to understand how harmonics work on a guitar, we must answer a more theoretical question such as “What is a harmonic?”

So let’s start there and then we’ll make our way up.

What Is a Harmonic?

A harmonic sequence is said to be a series of sounds whose frequencies turn out to be integer multiples of the frequency of a base note, which we can call fundamental.

In nature, each sound we hear has its frequency. Precisely, it is the frequency that makes a note or sound stand out different from the rest. For any sound we listen to with a particular frequency, there are many ( in fact, infinite) harmonics.

Now, suppose I have a sound wave that I consider to be my base parameter or pattern. This wave can be anything like, for example, the sound emitted by a guitar if I play an open string.

Well, believe me, if I tell you that the frequency of a guitar string (or any string instrument) depends on the length of the string. So if I want to get a sound that is half the original, I must play the string in half.

In this way, I am generating a harmonic whose frequency is twice that of the original.

To help you understand what I’m saying, here’s a great video to see how this works on a guitar.

The Physical Theory Behind Harmonics

Although it is a more difficult terrain to put into words, harmonics can be explained by a series of complex number additions called “Fourier Series” (link to Wikipedia) in honor of the mathematician Joseph Fourier.

Fourier demonstrated that if we add all the harmonics multiples of a fundamental frequency, that sum will converge to the original wave.

The reality is that the math behind harmonics is not some low-level calculation. And understanding them can be very difficult. So for now, let’s stay on the less numerical ground.

However, just keep in mind that this theory complements everything we have seen before and, in case you are interested, you can check this link (Wolfram MathWorld) to know more about it.

What Are Harmonic Sounds On a Guitar?

Harmonic sounds are sounds that are played either by amplifying the vibration of the original sound or by preventing it from spreading.

In both cases, an €œovertone€ is created, that is, a secondary sound that sounds in unison with the main sound and that maintains a certain harmony according to the laws of composition.

The harmonics that are played on a guitar are very high-pitched sounds and for this reason, in some countries, they are known as “over-sharp”, especially if played on an electric guitar.

These high-pitched sounds are impossible to achieve by stepping on the strings at the frets with your left hand, and therefore it is necessary to resort to a certain technique.

When a note is normally played on the guitar, the ear tends to hear the fundamental frequency, that is, the most prominent note. However, some secondary sounds play along with it. These add an overall warmth to the sound.

This physical phenomenon of sound is about a natural harmony, characteristic of each note and each instrument. Thus, the more harmonics sound along with the main note, the better the quality of the instrument, and consequently the better the quality of its sound.

However, the production of harmonic sounds can be produced and amplified by playing certain notes on the guitar and using certain techniques.

What Causes Harmonics On a Guitar?

What causes harmonics on the guitar are variations of the original string length. These variations generate alterations in the frequencies of vibration, and these alterations generate the harmonic sounds.

The open string is the base frequency, and when I put my finger on a fret, I am limiting the length of the string in halves, thirds, quarters, etc.

Each one of those mentioned variants is a harmonic sound.

Keep in mind that every time we decide to play a note, we are actually playing various harmonics. But it is also true that, in general, we will not listen to them.

If the instrument is good, it will be designed to “turn off” any harmonic that is generated when playing the string, except for one: the first harmonic or “the fundamental”.

When we say the fundamental, we mean the loudest sound produced by an open note. However, it is usually accompanied by other harmonics that will be difficult for us to perceive.

This brings us to the subject of artificial harmonics.

Artificial harmonics

Playing harmonics is nothing more than performing a specific technique to eliminate the fundamental harmonic and others highlighting a particular harmonic. These techniques produce the so-called “artificial harmonics”.

There are several special guitar techniques that allow a specific harmonic to sound, while the fundamental and the other harmonics are muted. This is called playing artificial harmonics.

Check out this video to see how it works.

Putting your finger on a string at the 12th fret, divide it into two equal lengths. If the string is pressed at that time, an artificial harmonic is created, an octave above the open string.

In the context of artificial harmonics, this eighth note is called the first harmonic, and not the fundamental.

What happens is this: putting your finger on the string creates a node or node point where the string doesn’t vibrate. This alters the vibration pattern that the string would have in the air, and the fundamental and other harmonics are prevented from sounding.

On either side of the node, two halves of the string vibrate in phase and produce the artificial harmonic. The points where the string vibrates the most are called anti-nodes.

If the length of the string is divided into three (exactly on the 7th or 19th frets), the frequency of the harmonic will be three times higher: one eighth and one fifth above the open string.

In theory, it is possible to continue producing higher and higher harmonics. In practice there comes a time when they are not heard.

I recommend reviewing this video with a version of Tommy Emmanuel using artificial harmonics to play Somewhere Over The Rainbow. The result obtained is really beautiful and it serves to understand the things that we can achieve by applying this technique.

Harmonics On a Guitar

The fundamental (open string): in the sound there are the fundamental and all the harmonics, but the fundamental is predominant.

5th harmonic (3rd fret…“): the string vibrates in six equal lengths, giving an artificial harmonic two octaves and a fifth above the open string.

4th harmonic (fret 4): The string vibrates in five equal lengths, giving an artificial harmonic two octaves and a third major above the string in the air.

3rd harmonic (5th fret): The string vibrates in four equal lengths, giving an artificial harmonic two octaves above the string in the open.

2nd harmonic (7th fret): the string vibrates in three equal lengths, giving an artificial harmonic an octave and a fifth above the string in the air.

4th harmonic (fret 9): the string vibrates in five equal lengths, giving an artificial harmonic two octaves and a fifth above the string in the air.

1st harmonic (12th fret): The string vibrates in two equal lengths, giving an artificial harmonic one octave above the string in the air.

4th harmonic (16th fret): the string vibrates in five equal lengths, giving an artificial harmonic two octaves and a greater third above the open string.

2nd harmonic (19th fret): The string vibrates in three equal lengths, giving an artificial harmonic an octave and a fifth above the string in the air.

How to Play Harmonics on Strings in the Air

The first, second and third artificial harmonics are the easiest to play.

With practice, you can play more. The technique of the right hand is the normal one, pressing the strings as always. The key is in the left hand, whose technique differs from the normal fret in two aspects.

First, you only have to touch the string with your finger, without stepping on the fret. Second, you have to place your finger directly on the fret in question, not a little behind as when you step on it normally.

The only exception is the 5th harmonic, which is played between the 3rd and 4th frets.

How to Play Harmonics on Stringed Strings

There is a technique for playing harmonics in which the fingers of the right hand are used, both for playing and for plucking the string. The string node is touched with the index finger of the right hand and then the string is pressed with the little finger (or with a finger pick).

The great advantage of this technique is that harmonics can be played not only on open strings, since the left hand is free to step on any note. If the index finger of the right hand is placed lightly on the string, exactly halfway between the bridge and the fret where the string is stepped, the octave harmonic of the stepped note will be obtained.

With this method, you can play a melody or a sequence of chords fully in harmonics.

An alternative technique, widely used by rock and blues guitarists, is to “pinch” the harmonics between the thumb of the right hand and the plectrum.

The pick is held so that it barely protrudes from the thumb, and then the string is pressed simultaneously with the pick and thumb. The effect of the plectrum pressing the string and the thumb cushioning it (in the right place) produces a dynamic harmonic effect.

This system gives better results in tread high notes. That brings us to the next subject: Pinch harmonics. How do they work and how to perform it properly?

How Do Pinch Harmonics Work?

In essence, these are also artificial harmonics. But, in practice, when we talk about pinched harmonics we are referring to a technique that is quite difficult to master.

To generate a pinch harmonic, precise tine mastery is required. This is one of the reasons why this technique is complicated for beginners.

The key is to hold the pick just off the bottom of the thumb, sticking out slightly. What we want to achieve with this is for the pick to touch the string. And then, we want the string to be immediately struck by the thumb to produce the harmonic sound.

In this way, the blow of the thumb and the pick against the string must be almost simultaneous.

It is also important that we know where to hit the string. Because if we don’t touch its sweet spot, the note will be muffled.

The ideal place to play is difficult to locate and depends on where the harmonic is produced. It should be played halfway between the fret that we are playing and the bridge.

Therefore, when we change the fret, this sweet spot will change place, forcing us to find it again.

As I said earlier, it is a difficult technique to handle.

Here is a great video by Blues Guitar Unleashed to see how to do this.

How Do I Make My Guitar Harmonic Louder?

When we want to play harmonics on a guitar, we rest our fingers (but not fully press) on the string at certain specific frets.

When managing to generate these harmonics, it is common that we encounter some difficulties so that they sound in the best way.

It may be difficult for us to balance the sounds – between the harmonic note and the rest of the notes – or we may have problems positioning the left finger correctly. We could even do all of this well and continue to struggle.

There are some things to consider depending on generating louder harmonics. Here below I leave a list of tips to take into account.

1. Make Sure To Play Directly Above the Fret

This may be somewhat obvious to you if you are already used to playing harmonics. However, it bears repeating: always put the finger of your left hand directly on the fret.

In this way, a stronger sound will be obtained for the most typical harmonics (frets 5, 7 and 12)

If, on the contrary, we put our finger just slightly away from the fret, we will drown the sound.

The location must be absolutely precise and will require practice. If the placement is correct, the harmonic will sound cleaner.

2. When Playing a Harmonic, Don’t Be Afraid and Make It Sound Loud.

Harmonics are naturally more “quiet” in essence than the fundamental notes of the guitar. That is why it is important that if we want to balance the volume of this type of sounds with the others, we must play the harmonics with strength.

Perhaps so much vehemence can feel a little strange or inappropriate. And this feeling is logical: because if we played a common note with such abruptness it would sound horrible.

However, with harmonics, this approach works and in a very good way.

3. Move Your Right Hand Towards The Bridge

It is possible to obtain a better sound for the harmonics if we move our right hand towards the bridge. In other words, if we move it away from the fretboard.

In this way, we generate a higher quality tone; a brighter tone so to speak. And by moving the right hand backward, we also avoid accidentally silencing some frequencies when playing.

Normally, the best sound quality is obtained when we play three-quarters of the length of a string.

Note that, for the lowest positions and for the open strings, to play three-quarters we must locate ourselves above the soundhole.

But, as we move to higher frets, shortening the length, we must move towards the bridge. We can play with these variables for a while to discover how the placement affects the sound.

4. Remind Yourself To Use New Strings

The correct vibration of the strings is essential to generate good harmonics. As the aging of a string progresses, it loses its ability to generate sharp harmonics.

It is even possible that with some old strings we won’t be able to obtain certain harmonics at all. Keep this detail in mind if all the points mentioned above do not solve the problem.

To resume all this and show you more things you should pay attention, I will leave a video about this right here.

What Are Natural Harmonics?

Natural harmonics are harmonics that occur naturally by their own construction at certain points of the guitar.

When we speak of natural harmonics, we refer to those that are performed by playing the open strings and that are very clear to hear when they are played on frets 5, 7 and 12.

To make them sound, we must place – almost gently touching – a finger of the left hand on the fret of the string that we need, (on the metal bar). Then we must press with the right hand, to finally remove the finger from the left hand leaving the harmonic to be released.

Keep in mind that a clearer sound is produced the closer we press to the bridge.

Here is a good tutorial on natural guitar harmonics.

What Notes (Frets On a Guitar) Are Guitar Harmonics?

There are common harmonics and some more specific ones. Let’s focus for a moment on the most typical harmonics, those that occur on the following frets:

Fret	What It Does
12th Fret (has a relation of 1/2 with the original length)	This harmonic gives us an octave above the sound obtained by the open string
7th Fret (has a relation of 1/3 with the original length)	It gives us an octave plus a fifth above the sound of the open string
5th Fret (corresponds to a ratio of 1/4 to the original)	Delivers two octaves above the sound of the open string
4th Fret (it has a ratio of 1/5 with respect to the original length)	It gives us two octaves plus a third above the sound of the open string
9th Fret (it has a ratio of 2/5; which is equivalent to 1/5)	It gives us the same as the 4th fret since the proportions are the same

There are graphics that can show us the locations of these harmonics.

In the following two articles, we can find images that help us locate ourselves on the mast.

First, I recommend you review this article from Guitar Lesson World and then this one from Fretsource-Guitar, both are an excellent complement to understand the location of natural harmonics.

Why Do Harmonics Work On Some Frets Only?

The explanation for this is quite simple if we understand the physical concepts and the definition of the harmonics.

Harmonics occur in places where the string is divided into halves, thirds, quarters, etc. That is, the string is divided into integers of its original length.

There are certain frets that, if we press on them to obtain a harmonic, we will not be dividing the length of the string up to an integer proportion. Therefore, there will be no harmonic there.

The explanation of this is simply a physical and mathematical question, but it will always be a matter of proportion to the length of the string.

However, there are “hidden” harmonics between two frets, it is a matter of trying and finding a point that segments the string in an integer proportion. For example, try going down past the fifth fret to the nut; There you will find some harmonic points that are not settled on any specific fret.

Let’s understand that frets are a very useful visual reference point, but they do not have to be related to the note produced.

It is a matter of playing and discovering the sounds that we can find. The difficulty of these hidden harmonics – which are not located on any fret – is then to locate the exact place where we must play to produce them.

Conclusion

I hope this article gave you valuable information and insight into the world of guitar harmonics. If you enjoyed reading it as much as I enjoyed writing it, I’m more than happy about it!

Don’t forget to check out other interesting articles from this site about various guitar topics and issues.

Cheers, and rock on!

Introduction