So let's perhaps define rhythm guitar in the context of this discussion. To that end I will quote a section from Wikipedia.
"In rock music, the most common way to construct chord progressions is to play "triads", each comprising a root, third and fifth note of a given scale, or four-note chords, which include the sixth, seventh or ninth note of the scale. In some cases, the chord progression is implied with a simplified sequence of two or three notes, sometimes called a "riff", that is repeated throughout the composition.
In heavy metal (or just "metal") music, this is typically expanded to more complex sequences comprising a combination of chords, single notes and palm muting.
The rhythm guitar part in compositions performed by more technically oriented bands often include riffs employing complex lead guitar techniques. In some genres, especially metal, the audio signal from the rhythm guitar's output is often subsequently heavily distorted by overdriving the guitar's amplifier to create a thicker, "crunchier" sound for the palm-muted rhythms."
Let the nominations begin.
