A resonator banjo has a wooden bowl fixed to the back. An open-back banjo has nothing behind the head, so you can see inside the rim. The resonator makes the banjo louder and brighter and sends the sound forward. That is why bluegrass players use resonator banjos. Open-back banjos are lighter and softer and are the usual choice for old-time and clawhammer playing.
What a resonator does
A banjo makes sound when the strings shake the bridge and the bridge shakes the head, which is the round drum skin. Sound leaves the head in both directions.
On an open-back banjo, the sound that goes backward runs into the player’s body and gets soaked up.
A resonator catches that sound and bounces it out the front, through the gap around the rim. The banjo gets louder, and the tone gets sharper.
At a glance
| Resonator | Open back | |
|---|---|---|
| Volume | Louder | Softer |
| Tone | Bright, sharp, ringing | Warm, round, plunky |
| Weight | Heavier | Lighter |
| Usual style | Scruggs style, three-finger picking | Clawhammer |
| Usual music | Bluegrass | Old-time and folk |
| Price | Often higher for the same quality | Often lower |
Why bluegrass uses a resonator
A bluegrass banjo has to be heard over a guitar, a mandolin, a fiddle, and a bass, and it has to take a lead break. The resonator gives it that reach.
The bright tone is part of the style too. The sound of Earl Scruggs and the players who followed him is the sound of a resonator banjo played with picks.
Most bluegrass banjos have a tone ring as well. A tone ring is a metal ring that sits on top of the wooden rim, under the head. It adds volume, sustain, and weight. A resonator banjo with a heavy tone ring can be tiring to hold for a long session without a good strap.
Why old-time players use an open back
Old-time banjo is played with the fiddle, not over it. A softer, rounder tone blends better. Clawhammer players strike down on the strings with a fingernail, and the open-back banjo gives that stroke a warm thump.
Open-back banjos are lighter, which suits long sessions and playing on a porch or a trail.
Read clawhammer vs Scruggs style banjo.
Can you play bluegrass on an open-back banjo?
Yes, at home and in a small, quiet circle. The rolls and the chords are the same. In a full jam, an open back will be hard to hear, and it will not have the bright tone the circle expects on a break.
If an open-back banjo is what you have, start on it. Learn your rolls and chords. Move to a resonator when you start going to jams.
Can you play clawhammer on a resonator banjo?
Yes. Some players do. The tone will be brighter and louder than the usual old-time sound. A resonator banjo may get looks at a strict old-time jam.
Taking the resonator off
On many banjos the resonator is held on by a few thumb screws. Take them out and the resonator lifts off. The banjo gets lighter and quieter.
It does not turn into a true open-back banjo. The metal flange that held the resonator still sticks out around the rim, and the rest of the build is for bluegrass. It is a fair way to try a softer sound or to practice at low volume.
Other things that shape the sound
The back is one part of the sound. These matter too.
The tone ring. With one, the banjo is louder and rings longer.
The head. A tight head is bright. A looser head is warmer.
The bridge and strings.
The setup. How high the strings sit and how the neck is adjusted change both tone and ease of play.
The picks. Metal finger picks make any banjo brighter and louder than bare fingers.
Playing softer on a resonator banjo
A resonator banjo is loud, and a jam needs backup at low volume. Pick with a lighter touch. Pick closer to the neck, where the tone is rounder. Vamp in place of rolling when a quiet instrument has the lead. Read how to play banjo backup in a bluegrass jam.
For practice at home, players stuff a small towel inside the back or clip a mute to the bridge.
Which one to buy
To play bluegrass and go to bluegrass jams: a resonator banjo.
To play clawhammer and old-time music: an open-back banjo.
Not sure yet: a resonator banjo with a resonator that comes off gives you both sounds to try.
For either kind, a good setup matters more than the price tag. Buy from a shop that sets up each banjo, or have a repair person check a used one.
What else you need
A strap. A resonator banjo is heavy.
A thumb pick and two finger picks for bluegrass.
A capo, and a way to raise the fifth string. Read how to use a capo in a bluegrass jam.
A tuner. Read what to bring to a bluegrass jam.
Then learn your first rolls. Read banjo rolls to learn first. For more on the instrument, see the bluegrass banjo guide and the list of bluegrass banjo players.