I talk a lot about harmonics when I’m talking about EQ or saturation – anything which deals with the frequencies of audio. With that in mind, I thought I’d put together a quick definition as the title suggests of what are harmonics in music.
What Are Harmonics
As they relate to music, harmonics are higher octaves of the fundamental frequency of a note (including the initial octave itself). Virtually every noise you hear has harmonics which ring out as part of that note.
Let’s use a practical example to better demonstrate what are harmonics in music.
The fundamental frequency of an open low E string on an acoustic guitar (in standard tuning with a 440Hz reference) is 82Hz.
An octave up means that we’re doubling the frequency, so an octave up from a low E on the acoustic guitar is 82×2, or 164Hz (which is also unsurprisingly the fundamental frequency of the next E note on the guitar).
If we pluck that 82Hz open E string on the acoustic guitar and look at it using a visual analyzer like our FabFilter Pro-Q 3 equalizer, we see its fundamental frequency at 82Hz but see another large peak at roughly double that value – this is one of its harmonics:
Saturation is an effect which introduces distortion to audio in order to create harmonics and overtones to fill out the sound.
While EQ can’t be used to boost something which isn’t there, saturation can fill out otherwise thin or empty sounding audio by creating frequency information where it didn’t exist before via those harmonics.
A very simplified example to demonstrate this is to take the simplest of sound waves, a sine wave, and apply saturation to it to show the before and after frequency profile:
As you can see, applying basic saturation to a simple sine wave which was previously exclusively vibrating at 110Hz creates harmonics at the octaves and even some overtones at and in between the multiples.
Check out my many saturation tutorials on how to use it in your mix to adjust the tone of your mix’s various tracks and instruments for the better by way of adding harmonics (and overtones).
