The most important role of the guitar in Bluegrass is a rhythm instrument. In the early Bluegrass recordings, the guitar often never took a lead break at all. Just a few bass runs, and the rest was rhythm. Today it's common for guitarists to take lead breaks in bands, but even then the guitarist is playing rhythm 80% or more of the time.
Rhythm Guitar Roles
As a rhythm instrument in bluegrass, the guitar serves several roles:
It acts like a metronome to keep the tempo constant. In most situations, the rhythm guitarist will place the emphasis on the off beat rather than the down beat. In a tune that is 4/4 time that means that the guitar is emphasizing beats 2 and 4.
It fills the tune with notes besides the main melody. While the lead instrument is playing a single note melody, the guitar is adding the other notes in the chords of the song.
It adds ornamentation to rests and turnarounds. The guitar can add short phrases when there are rest measures in a song. The most common place that you will hear this is in turnarounds, where the guitarist might add a lick like the famous G-run.
Playing rhythm requires you to:
Learn the basic chord shapes in several keys (C, G, and D are the important ones)
Develop a rock-solid sense of timing to keep the beat (metronomes help)
Learn how to vary your rhythm patterns with different time signatures and tempo
Learn how to play bass runs to transition between chords
Always remember that you're part of a band, and develop an awareness of how your playing is contributing to the whole sound
Open chords are the most typical shapes used by Bluegrass guitarists. These are the standard shapes that you would learn in beginning guitar books. Barred chords and closed form jazz-style chords are not commonly used.
The G-run is one of those signature guitar licks that seems to get into every bluegrass song. It's origin is attributed to the great Lester Flatt, who played with Bill Monroe and later with his long time friend Earl Scruggs in the Foggy Mountain Boys.
The guitarist has little opportunity for inserting much lead playing into Bluegrass songs when playing rhythm, but there are places where there are opportunities for short licks. These typically occur in turnarounds between verses. The singers or lead musicians take a short break then, and that's where you'll typically hear the G-run played.
The G-run comes in many styles and keys. We've included examples of the most common in our Rhythm Tabs Page for G-runs.
Looking for Rhythm Guitar Tabs?
Be sure to check out our Rhythm Tab Page for exercises to help you learn rhythm technique. These include basic rhythm patterns, g-runs and walking bass exercices.