Overtones and Harmonics of Guitar Strings

By Nick Mancuso

Table of contents

Intro

Graphs

Intro to the whole thing

There I was playing a little Rock You Like A Hurricane on my guitar. Now Rock You Like A Hurricane requires you to use palm mutes. Palm mutes if you do not know requires you to mute the string with the palm of your hand. As I was doing this I was wondering, why does it sound the way it does? Why does it sound like a banjo when you play it near the bridge? Then suddenly it hit me, harmonics. All strings have harmonics, the set of sounds overlaid on the fundamental, the pitch you hear. Upon thinking about this I came to believe that the closer you are to the bridge and the nut, the upper bridge, the more overtones, or harmonics, you get.

First thing I did was measure the length of the strings at different spots. I chose the bridge, the bottom of that big O, the middle of that O, the top of said O, the 9^th fret, and the nut. Then I got a microphone, a computer, and some spiffy sound software, and recorded the overtones I measured at those points.

where you pluck the string determines how the string vibrates. when you pluck a string it vibrates with nodes at certain places. Each node is a different harmonic or overtone. The more nodes you have the more overtones you have. With the graphs I found that the closer you play to the top of the O and the 9th Fret, at least on my guitar, it would be different for all others, the least amount of overtones are played and the more the fundamental pitch is heard.

This is a string with only the fundamental playing. On my guitar this would be about midway between the 9th fret and the top of that big O

This is a string with the fundamental and one overtone playing. On my guitar this would be just offset of the previous pictures location.