What Are Overtones (the simple answer)

What Are Overtones? (the simple answer)

If you’ve been around music for a while you’ve probably heard reference to overtones. But do you understand what an overtone is? To make things even more complicated, some people speak of harmonics when they mean overtones or they speak of overtones when they mean harmonics.

In this article we’ll guide you through the world of overtones and make it as easy to understand as possible. Let’s start with a dictionary definition and take it from there.

Overtone

[ usually plural ]

something that is suggested, but is not clearly stated:

PHYSICS, MUSIC   specialized

a frequency of a sound that is higher than the fundamental (= the lowest normal frequency)

Cambridge Dictionary

Believe it or not, the two statements above, sum up overtones pretty well. But that’s easy to say especially as we have a certain level of understanding of overtones.

Overtones Explained

Keep in mind those two definitions above as we go through this simple explanation of overtones in relation to music. If you pluck a guitar string, any string but in this case the high E while pressing the fifth fret, you’ll be playing the A above middle C. So far so good but, and this is where it gets interesting, that’s not the only note you’ll be able to hear.

The note you intended to play in this case, the A above middle C vibrates at 440 hertz which means it vibrates 440 times per second. As it’s a string, it vibrates or oscillates and although the fundamental sound is the A above middle C, other notes can be heard as well. This is due to the way sound waves work, in other words, nature creates this effect.

Playing The Guitar

The Laws Of Physics

When the string is plucked, the fundamental note rings out the loudest and we perceive it as the A note we were aiming for. But due to natural laws of physics, if you listen closely you’ll be able to hear other notes. These other notes always follow the same pattern which is,

  1. The fundamental (in this case A)
  2. The same note one octave higher (1st overtone)
  3. The perfect fifth above that (2nd overtone)
  4. Two octaves above the original (3rd overtone)

It doesn’t stop there but that’s enough to give you a clear idea of what’s going on. 

Harmonics

Now let’s explain why some people refer to overtones as harmonics. What we’ve just seen above are the overtones of the original A note which are created when the high points of two sound waves overlap. So the sound waves of the original note and the note one octave higher will overlap at some point and create an overtone. 

The pattern of notes above are the overtones, but they can also be expressed in terms of harmonics;

  1. 1st harmonic or fundamental (in this case A)
  2. 2nd harmonic (the same note one octave higher) AKA 1st overtone
  3. 3rd harmonic (the perfect fifth above the octave note) AKA 2nd overtone
  4. 4th harmonic (two octaves above the original note) AKA 3rd overtone

Back To The Definition

Now the dictionary definition looks clearer, remember, something that is suggested, but is not clearly stated. The only clearly stated note is the fundamental A note, but the overtones are suggested (heard but not heard clearly). And of course, a frequency of a sound that is higher than the fundamental.

In Plain English

In music an overtone is all of the other notes that create the rich sound often called the timbre that makes a full note. In essence each note actually contains the whole of its sound, the root, 3rd, 5th, and so on but we only truly hear the root note. These overtones can also be called harmonies.

guitar chords

Two Different Types Of Overtones

Overtones follow the same pattern but the higher up the frequency chain it goes, the notes differ. This creates two totally different, yet connected types of overtones. Which are;

  • Harmonic Overtones
  • Disharmonic Overtones

Harmonic Overtones

These sound in tune with the fundamental note and therefore compliment the sound of the whole.

Disharmonic Overtones

These resonate between the accepted tones that make a note or chord, and sound discordant or out of tune and negatively affect the whole.

The Barbershop Quartet Effect

To the untrained ear, all that can be heard is the fundamental note, but to the experienced musician, the overtones become clearer. This is often evident among barbershop quartets, four singers, singing A Cappella. There can only be four voices because there are only four of them singing, but another sound appears.

No one singer is producing this other sound, it is a product of the overtones from all four voices. This is only possible if all four singers are singing in perfect pitch. Plus overtones are easier to detect if you are pitch perfect.

Overtones – A Summary

Any frequency above the base frequency of any note can be described as an overtone. Or to put it another way, overtones are any higher pitches of the fundamental note.

The note you play is in general terms, the main sound you can hear. However, the overtones of that note are always present, it’s just you can’t always hear them. 

Frequently Asked Questions

What is meant by overtones in physics?

In physics, overtones are any frequency above the fundamental frequency.

Do all instruments produce overtones?

All instruments do produce overtones, even the human voice when being used as an instrument (singing).

Are all harmonics overtones?

All harmonics are overtones.

What is difference between overtone and harmonic?

The difference between an overtone and a harmonic is an overtone is the general term applied to any high frequency wave. A harmonic is the term used if the frequency of the overtone is in tune with the fundamental.

What is the lowest sound of an overtone series called?

The lowest sound of an overtone is called the fundamental.

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