A banjo is a drum with a neck bolted to it. The drum is a wooden hoop with a sheet of polyester film stretched over it and clamped down by a ring of steel hooks; the neck is a single piece of hardwood carrying a fretted fingerboard; the strings are steel. Everything else — the metal ring under the head, the bowl on the back, the plating on the hardware — is a variation on those four things.
Three of those materials decide what the instrument sounds like: the wood of the rim, the metal ring sitting on top of it, and the film stretched over both. Two of the three can be changed in an afternoon for under fifty dollars, which is the useful thing to know about how a banjo is built.
Every part, and what it is made of
| Part | Material | What it does |
|---|---|---|
| Rim (the pot) | Laminated maple, usually three plies; mahogany or birch on cheaper instruments; molded composite on the lightest ones | The body of the drum. Denser wood, brighter and louder |
| Tone ring | Cast bell brass or bronze, rolled brass, or absent altogether | The head presses against it instead of bare wood. Three pounds of cast metal is what makes a bluegrass banjo loud |
| Head | BoPET film — Mylar. Animal skin on historical and replica instruments | The vibrating surface. The single biggest change you can make for the money |
| Tension hoop | Beveled steel, or notched brass | Clamps the head’s aluminum flesh hoop down onto the rim |
| Hooks and nuts | Nickel- or chrome-plated steel; 16 on an open back, 24 on most resonator banjos | Pull the tension hoop down. Tightening them tunes the drum |
| Bridge | Maple with a thin ebony cap, three feet, 5/8″ tall as standard | Carries the strings’ vibration into the head. Not glued — it stands under string pressure |
| Tailpiece | Steel alloy, plated | Anchors the strings and sets how hard they press on the bridge |
| Neck | Maple, mahogany or walnut; nato, sapele or okoume at the budget end | Stability first. The wood matters far less here than in the pot |
| Fingerboard | Ebony on expensive banjos, maple, rosewood, purpleheart or ovankol elsewhere | Wear surface under the strings |
| Frets | Nickel silver — a copper-nickel-zinc alloy with no silver in it | Stops the string at a defined length |
| Nut | Bone, plastic or hardwood | Spaces the strings and sets their height at the top of the neck |
| Truss rod | Steel | Runs inside the neck and adjusts its curve against string tension |
| Tuners | Die-cast metal gears, usually with plastic or pearloid buttons | Hold the tuning. The fifth-string peg is often geared as well |
| Resonator | Laminated maple or mahogany, with a cast zinc flange | Only on closed-back banjos. Reflects sound forward |
| Dowel stick or coordinator rods | A single hardwood bar, or one or two steel rods | Joins neck to pot and sets the neck angle |
The pot is a drum, and it is mostly maple
The rim is a hoop of laminated wood about eleven inches across and two and a half deep. Maple is the standard because it is dense and stiff, and because laminating it in three plies with the grain alternating makes a hoop that will not go oval when a head is torqued down on it. Deering’s Goodtime line is built on a three-ply violin-grade maple rim; the same shape in mahogany or birch, which is what most instruments under $300 use, gives a warmer and less penetrating note.
Sitting on top of the rim, on some banjos, is the tone ring. On a bluegrass instrument this is a cast bell-brass hoop weighing about three pounds, and it is most of the reason a bluegrass banjo weighs eleven pounds while an open back weighs four and a half. Old-time banjos often use a much lighter rolled brass bar, and plenty of good instruments — the whole Goodtime line included — have no ring at all, with the head bearing directly on the wooden rim. That is a choice about voice, not about quality. There is more on the trade-off in our guide to open back banjos, and on what the ring costs you in what a banjo weighs.
Whether there is a wooden bowl screwed to the back is a separate question from all of this, and it is covered properly in open back versus resonator.
The head is plastic, and it is the part to change
The white surface stretched across the front is a single sheet of BoPET — biaxially oriented polyester film, sold under the name Mylar — crimped into an aluminum hoop. It replaced calfskin and goatskin in the 1950s and 60s for the obvious reason: skin goes slack when the weather turns damp, and film does not.
Film comes in several finishes, and swapping one for another changes the instrument’s voice more than any other twenty-dollar decision. A frosted or coated top has a fine matt coating that damps the highest overtones: crisp, snappy, quick to decay, and the head almost every banjo leaves the factory with. A clear head is bare film, so it is the brightest and most open. Fiberskyn is film with a fibrous surface that looks and sounds like old calfskin — round, dry, plunky, the clawhammer favorite. Renaissance is honey-colored and sits between frosted and Fiberskyn, warmer than one and clearer than the other. A black head is the mellowest, with the longest sustain.
Two numbers have to match before you order one. The first is diameter: eleven inches covers almost every banjo built, with twelve inches reserved for the deep-voiced old-time instruments. The second is crown height, the depth of the collar between the aluminum hoop and the playing surface — 3/8″ for low, 7/16″ for medium, 1/2″ for high. Get it wrong and the head either bottoms out before it is tight or has nothing left to grip. Medium is the safe answer if the banjo came with no paperwork, but the makers publish theirs: every eleven-inch Deering Goodtime takes a high crown, while the twelve-inch Americana and the current Deering upper line take a medium.
Remo WeatherKing 11″ Frosted Head
The standard white frosted Mylar head, eleven inches, in the high crown that fits Goodtimes and most older banjos. A fresh head on a banjo that has had the same one for ten years is a bigger difference than anything else you can buy for the price of two sets of strings.
The bridge is two woods and it is not attached to anything
The small three-footed piece carrying the strings across the head is maple with a strip of ebony glued along the top. Maple is light and stiff, so it passes the strings’ energy into the head rather than absorbing it; the ebony cap is hard enough that the steel strings do not saw grooves into it. Nothing holds the bridge down but string pressure, which is why it walks out of position over time and why it is the easiest upgrade on the instrument — the stock bridge on a cheap banjo is usually its worst part.
Grover #73 Banjo Bridge
- Maple body, ebony cap
- 5/8″ tall, the standard height
- Three feet, for a five-string
- ~$14
Measure the old one before ordering. A taller bridge raises the action and a shorter one lowers it, so 5/8″ is only the right replacement if the banjo already had 5/8″ on it. The other thing worth doing while the strings are off is checking the feet sit flat on the head — a bridge rocking on one foot is losing you volume no material will give back.
The strings are steel, and lighter than you would guess
The three unwound strings are plain high-carbon steel. The wound ones have a steel core with nickel-plated steel or phosphor bronze wrapped round it — nickel is brighter and phosphor bronze warmer, and on a banjo the difference is small enough that gauge matters more. A five-string set runs from about .009 to .023, far lighter than any guitar set, and the pot is only under that tension because the head is doing most of the work of making the sound. Nylon and Nylgut sets exist for gut-strung old-time and minstrel playing, on instruments built for the lower tension.
Which set to buy is its own question, and we have gone through it in the best banjo strings. How many of them there should be is answered in how many strings a banjo has — four, five and six are all normal, and they are different instruments rather than different sizes.
What the materials cost
Price on a banjo buys materials in a fairly predictable order: first a real wooden rim instead of a molded one, then a properly seasoned hardwood neck, then a tone ring, then American labor. The gap between a $175 banjo and a $600 one is narrower on the spec sheet than the prices suggest.
| Banjo | Rim | Neck and board | Tone ring | Price band |
|---|---|---|---|---|
| Jameson 5-String | 5-ply maple and mahogany | Mahogany neck, purpleheart board | None | ~$175 |
| Deering Goodtime | 3-ply violin-grade maple | Hard rock maple, maple board | None | ~$600 |
On paper those are closer than the prices suggest — both are laminated maple pots with no tone ring, and the Jameson arrives with a Remo head and a maple-and-ebony bridge already on it. What the extra money buys is consistency: seasoned wood that has stopped moving, frets leveled by someone who checked, and a setup done before the instrument was boxed. At the cheap end that work has not happened, so budget $50 to $100 for a setup on top and the gap narrows a good deal further. Our beginner banjo guide takes that argument further, and what a banjo costs covers the ladder above it.
Where the materials came from
The banjo descends from West African gourd lutes — the akonting, the ngoni, the xalam — carried to the Americas by enslaved people, and the earliest instruments were built from what was available: a gourd for the body, an animal skin tacked over it, a wooden neck, and gut strings. The seventeenth-century descriptions are of exactly that, a gourd with a neck fastened to it.
Every material on a modern banjo is a nineteenth or twentieth-century replacement for one of those four. The gourd became a steam-bent and then laminated wooden hoop. The tacked skin became a skin clamped by a metal tension hoop, so it could be tightened, and then plastic film so it would stay tight. Gut gave way to steel, which is what made the instrument loud enough to cut through a string band. The metal tone ring is the newest part of all, and it exists only because players wanted more volume still. If you want to work out how old a particular instrument is, those transitions are the evidence — we have laid them out in how to tell how old a banjo is.
Common questions
What wood is a banjo made of?
Maple, mostly. The rim is laminated maple on any banjo built to sound like one, and the neck is maple, mahogany or walnut. Fingerboards are ebony on expensive instruments and maple, rosewood, purpleheart or ovankol on the rest. Mahogany and birch turn up in the rims of cheaper banjos and give a softer note.
Are banjo heads still made of animal skin?
Almost never. Plastic film took over decades ago because it holds its tension through changes in humidity. Goatskin and calfskin heads are still made and still fitted to minstrel banjos and period reproductions, and they have a soft, dry voice nothing synthetic quite matches — but they need retensioning as the weather moves, which is why nobody gigs on one by accident.
Does the tone ring really matter?
It changes the voice, not the quality. A three-pound cast ring gives the cutting, bell-like bluegrass sound and adds six pounds to what you carry. A light rolled brass bar brightens an old-time banjo a little. No ring at all is the traditional open back arrangement and is what most clawhammer players want. There is no version of this where the banjo with the ring is simply the better instrument.
Can I change what my banjo is made of?
The three parts that most affect the sound are also the three cheapest: the head, the bridge and the strings. All three come off with a bracket wrench and a screwdriver, and together they cost less than fifty dollars. The rim, the neck and the tone ring are structural, and changing any of them is luthier work worth more than most banjos.
Why is the fifth string shorter?
Because it is a drone. It runs from a peg set into the side of the neck at the fifth fret and is tuned high, and it sounds the same note whatever the left hand is doing — that ringing note under everything is the sound people identify as a banjo. There is more on the family in our guide to types of banjos and on the wider group in string instruments.