Palm muting is something that can be difficult at first, but is easy once you get used to it. This technique is commonly used in heavy metal, and is what produces that heavy crunching sound.

You perform palm muting by gently placing the palm of your right hand on the strings near the bridge, while playing your desired strings. So basically, you are muffling the sound. Be sure not move your right hand too far away from the bridge, otherwise you will completely mute the strings and you'll just hear a raking sound.



So on the example below, you would play the chord shown, after you have placed your right hand on the strings in the correct place. PM is short for palm muting...

PM...
e|---------|
B|---------|
G|---------|
D|----2----|
A|----2----|
E|----0----|

This isn't really enough to get the idea of palm muting, so it would be best to try out the example below to fully develop your understanding of palm muting. This example combines palm muting with power chords. Try it slowly at first, then try and get it faster as you improve...

_|____PM...._____PM...._____PM....________|
e|----------------------------------------|
B|----------------------------------------|
G|-2---2--2---2---2--2------------------7-|
D|-2---2--2---2---2--2---2---2--2---5---7-|
A|-0---0--0---0---0--0---2---2--2---5---5-|
E|-----------------------0---0--0---3-----|

Listen