Tuning Stability
Wrtten by Barry Hunn
How long should a banjo stay in tune?
This is a question that is dependent mostly on the technique of the player and the set up and quality of the banjo.
The Banjo
Some aspects of the banjo that affect tuning stability are the movement of the bridge on the head, the flexibility of the tailpiece, changes in the room temperature, the way the strings fit in the nut, the tuning machines and the fit of the heel to the rim. These are others, but these are the easiest to determine by the player and cover the majority of issues on most banjos. There are issues like glue joints failing, laminated rims separating, cracked aluminum rims or defective truss rods but these aren’t as common on good banjos and virtually non-existent on Deering banjos. (we don’t make banjos with aluminum rims, but I have seen import banjos with cracking aluminum rims.)
The bridge on a banjo head can be moved by hard, aggressive playing, warming or cooling of the banjo head, pushing the bridge with the fingers and the natural stretching of the head. Playing hard, or plucking the strings very hard, will move the bridge, literally by pushing the bridge by force of the fingers plucking the strings. Smooth topped heads allow the bridge to slide easier than heads with a rough surface. Players with a light touch don’t tend to move the bridge, unless they hook a finger on one edge of the bridge, which sometimes moves the bridge slightly. Sometimes ending a song with a loud brush across the strings will move the bridge and knock the banjo out of tune.
If a room is warm, and a cool breeze blows across the head, the plastic head will “tighten” or “shrink slightly” changing the string pitch. If the room is cool or cold and warm sun begins to shine on the head and warms it up, the head will “soften” or “stretch” from the heat and sag slightly, changing the pitch of the strings. Nothing can be done about this other than playing in an environment that is completely stable….not very realistic.
Some tailpiece designs are light weight brass or pot metal and have some “flexibility” in them that makes tuning stability almost impossible. The better tailpieces are rigid to solidly anchor the strings. When we pluck the strings, we are bending them and releasing them which, like shooting arrows from a drawn bow, pulls on the tailpiece. If the tailpiece is flexible, it doesn’t always flex back to exactly the same position. It’s position changes when it is flexed. The strings shift on the leading edge of the tailpiece if the bridge slides around. If you look at Deering’s “true tone” tailpiece, you’ll see that it is not only extremely rigid but the strings are rigidly locked into individual places on the leading edge nearest the bridge but yet the design makes the strings easy to change. Many older and import copy tailpieces are made of light weight, flat, thin metal that bend easily which makes tuning stability impossible. If you have a light, flimsy tailpiece, be good to yourself, replace it. (See Deering’s true tone tailpiece)
If the strings don’t slide freely through the string nut, (the slotted piece that guides the strings up near the tuning machines.) they can “stick” in the notches of the nut. When the string is pulled by plucking, it is now freed from being stuck, but is at a different pitch than when it was tuned and stuck. This can be eliminated by rubbing a sharpened #2 pencil in the string notches, leaving some of the powdered graphite of the pencil in the string notch which acts as a dry lubricant to prevent the string from “sticking” in the notch. Oils and waxes can not only damage some nut materials but also attract dust and dirt and some oils and waxes will harden or turn gummy…dry lubrication is the only workable solution for sticking strings.
Banjoists who use “Scruggs Tuners” or “D-Tuners” need string nuts to be as lubricated as possible so that every D-tuning they execute brings the string back to the correct pitch. The string notches must be cut with the right width of course, but some nut materials seem to get “sticky” from steel strings rubbing through the notches over time and the dry graphite treatment of the #2 pencil is the best, cheapest way to keep the strings sliding freely. Don’t widen the notches too much as this can not only change your string spacing, but if the strings can slide left to right in the slot, you now have another stability issue. The craftsmanship of a good banjo is represented by strings that are held “firmly” so they are stable but “relaxed” in the notches of the nut and the bridge so they move freely. Every banjo will benefit from the pencil graphite in the nut.
If the heel of the neck of a banjo is not cut to fit precisely against the rim, the banjo will never be stable. At Deering, we go through immense effort to make each and every heel cut as perfect a fit to the rim as possible. Heel cuts that are lumpy, un-even or not consistent with the two mating curves of neck and rim, cannot be tightened to the rim firmly with any amount of fastening tension. This is one reason the Goodtime banjos sound so good compared to many other lower priced banjos… the fit of the heel to the rim. This firm neck connection prevents sound loss. Lose parts absorb vibration. Correctly fitted parts transmit or transfer vibration. If the neck rocks, or wobbles due to a lumpy surface on the neck joint, then every time you pick up the banjo, or play a chord or shift the banjo on your lap, the banjo will be out of tune and sound dull because the neck is moving, not rigid.
Keeping the neck tight against the rim, as long as the heel is cut correctly, keeps the banjo stable. If the neck is loose, then every time you touch the neck, it moves; and if it moves it changes the pitch of the strings and it cannot stay in tune. Have your neck checked for tightness. If it is loose, snug it tightly against the rim. (see our online maintenance manual for instructions) If tightening the neck doesn’t prevent shifting, get a new banjo.
Because banjo necks can come loose, part of regular maintenance is to check the tightness of the neck to the rim. Violins have necks that are glued to the body. But violinists tune regularly during performances. Guitars have necks and bridges glued to hard wood surfaces. Yet, many guitarists still need to tune between songs in concerts.
Tuning machines come in two types for banjos. One is the “guitar style” with knobs that stick out to the side. The other are called “Planetary tuners” which stick out toward the back of the banjo. “Guitar style” tuners tend to have greater leverage because of the design of the relationship between the gears. Unless a gear or shaft breaks and they fail completely, they have less issues with “slipping”. The screw on the end of the tuner does hold the string tension a bit, but the right angle design of this tuner’s gears don’t require much tightening as the screw is mostly needed to hold the button in place.
Planetary tuners have a screw in the end of the tuner which not only holds the tuner button on the shaft, but it also creates a bit of friction to prevent the tuner from “slipping” under the pulling tension of the strings. If the screw in the end of the planetary tuner is too loose, the string can pull the tuner enough to turn it and the string will go flat. Usually, if the tuner is not defective, tightening this screw will increase the tuner’s resistance and the string won’t go flat. The balance with planetary tuners is to keep the screw tight enough just to keep the tuning but not so tight that the tuner is difficult to turn. The better the tuner, the smoother and lighter the tuning ability.
Strings stretch quite a bit when they are new. This makes tuning your banjo difficult when you just put on a fresh set of strings. The steel has certain amount of “stretch” in it. How long it takes for strings to lose the stretching is hard to say. The stretchiness time of new strings is somewhat relative to how much they are played. The more you play, the sooner the strings will lose much of their stretch-ability. If new strings are installed and the banjo is left alone it is likely that most strings will have stretched into place in about two weeks. This is just a rule of thumb and not final.
Technique
If you pluck a banjo string hard enough the bridge will move. If you rest your picking fingers up against the bridge, it is very easy to push the bridge and change the pitch. Moving a banjo bridge as little as one thousandth of an inch changes the pitch of the strings. (a typical light gauge banjo first string is ten thousandths of an inch…think about moving your bridge one tenth of that string’s thickness… not very much to throw off the tuning….something to think about.)
If you press down on the head of the banjo with your resting fingers of you picking hand while you play, that can deflect the head enough down to change the pitch of the strings. If you press hard during one song and then press lightly on another song, you’re changing the pitch of the strings with every different pressure of the fingers on the banjo head and you’ll need to re-tune. Sometimes we “push” our picking hand harder into the head during fast songs than on slow songs. This habit will make you feel that your banjo always goes out of tune.
The awareness of this picking hand pressure on the head is particularly important when tuning your banjo with an electronic tuner. If you push the head firmly while plucking one string and then push the head lightly or not at all when tuning another string, those strings will not be in tune with each other because you changed the position of the bridge by pushing the head differently each time. Consistency is the key for accurate tuning.
Because the five and four string banjo necks are very thin, if you pull or push the neck during playing, it will change the pitch as you play. Some players do this deliberately as a kind of “vibrato” technique. Some strong armed players aren’t aware that their grip and arm are flexing the neck and they think the banjo is “going out of tune” by itself, when they are actually pushing or pulling it themselves. The banjo strap should be fastened to the pot or body of the banjo and not to the neck. I know, some famous players fasten the strap to the neck but they are definitely in the minority and they must have worked around the tuning distortion issue by some technique.
How you fret the strings affects the tuning of a banjo. Taller frets make fingering faster and require less finger pressure. You only need enough pressure to push the string down to the top of the fret. Pushing the string all the way down to the fingerboard makes the string play sharp with tall frets. Some older banjos had tiny, thin, short little frets and fretting was slow because you had to practically push the strings all the way to the fret board. If this technique is used on a modern banjo with taller frets, the string is being stretched over the taller fret and stretched “sharp” in pitch. Players who are used to shallower frets tend to over fret or over play the taller fret banjos and they can’t get the banjo in tune because they don’t “stretch” the string uniformly while tuning. Watching your technique for a few weeks usually is enough to adapt to the proper fretting pressure. Then both tuning and playing become more precise and uniform. It just takes a little time to adapt.
Pushing the string straight down or pushing or pulling the string to one side or the other makes a difference in tuning. If you push to one side or the other, you are stretching the string. If you train your finger to push straight down, with only enough pressure to just make a clear sound, you will create the clearest sound with the least effort.
If you are tuning with an electronic tuner, and you fret one string hard and another string soft, your banjo will never be tuned because you’ve stretched one string over the fret further than the other. If moving the bridge one thousandth of an inch changes the pitch of the strings, imagine what pushing a string 10 or 15 thousandths of an inch beyond the fret will do. When you fret at different places on the fingerboard, your wrist and elbow have to bend or twist in different directions which naturally causes your fingers to grip tighter or looser because of the posture of your whole arm. Fortuneatly, with practice, you develop a more even touch with all fingers on all frets.
How long do banjos stay in tune?
Depending on your playing technique, banjos can stay in tune for one song or twenty. You might play softly, but push or pull your neck a lot. You might play with a strong attack and handle your neck with kid glove gentleness and not go out of tune for several songs. It is not unusual to tune a banjo after every song. You might be playing in a building where the ambient temperature doesn’t change much at all and the banjo stays in tune for a whole concert. On the other hand, you might be playing outside where you can’t make it through a song because the sun shines and goes behind a cloud so the head is warm and then cools off. Even guitars and fiddles struggle during those kinds of changes. While changes in humidity won’t affect a plastic banjo head, they do affect the wood and can swell or shrink the neck and rim and sometimes quickly.
There are so many variables that can change a banjo’s tuning that players over the years have developed techniques to keep their instruments in tune through temperature, weather and handling changes. It is interesting that like the finest violins in the world, the best banjos in the world are the most sensitive to changes. Think about it, the head of a Deering banjos starts with a mylar film that is ten thousandths of an inch thick. If it has white frosting sprayed on it, that coating adds a little to the thickness…but you’re still looking at a thin membrane, stretched over a bell metal tone ring, which is carefully fitted to a three ply maple rim and then you add expansion and contraction during weather changes… it’s easy to see how such a precise yet delicate system needs care to stay stable.
Some players think that their banjo should stay tuned until they change it; whether for one picking session or one year. This is not realistic. After attending many concerts with some of the greatest banjoists in the world, who play some very famous and popular banjos and watching them tune regularly between songs, we have seen that banjos are sensitive and need to be tuned regularly, even by the most famous and proficient performers. It is true that professional players can often hear tiny pitch differences more acutely than some of us who are casual players, but it is also true that banjos, violins, and other stringed instruments require frequent tuning while performing.
Just like technique in playing the banjo, there is technique in keeping your banjo in tune. Treat your banjo gently. Don’t push the neck while playing. This is one reason to always use a strap. Pick up your banjo by holding the neck and the pot (body of the banjo). Keep your banjo adjusted with all the parts tight. Change any parts that are flimsy or not rigid enough.
Also, know that when the sun comes up or the wind changes or the air conditioner starts blowing, your banjo will change. Practice tuning by practicing your banjo more. Practice a little each day and tune a little each day. In time, your speed of tuning will increase and you’ll not dread the tuning changes, you’ll roll with it. (no pun intended.)
