Tuning your mandolin
If you are looking at this page it is probably because you have experienced problems in tuning your mandolin. Unfortunately such problems are a fact of life with this instrument! I thought it would be worth analysing some of the difficulties and looking at ways of alleviating them. There is unfortunately no miracle cure, but being aware of what you are up against can help you to focus on the problem.
I'm assuming you've read the instruction books which tell you that you should ensure that the note at the seventh fret of each string should correspond to the note of the next highest string played open. (All the books say this.) This is OK for approximate tuning, assuming your instrument is properly set up (see below), but it will still probably not sound quite right.
How to tune
If you want to cut the theory and discussion, you should just do the following:
- Use new(ish) clean strings.
- Ensure the bridge is in its optimum position and that the saddle is not tilted.
- Ensure that the strings are not binding excessively in the nut and bridge slots. (They always bind to some extent.)
- Tune each string accurately, using an electronic tuner. The notes are E A D G , 1st pair to 4th pair, the two strings of a pair being in (exact!) unison.
- Play a range of chords in the first position, and adjust the tuning so that all of the chords sound as harmonious as you can get them. Compare 12th fret harmonics with the corresponding notes at the 5th fret, e.g. third string harmonic at 12th fret compared with second string stopped at the 5th fret.
- Play the mandolin solidly (chords and melodies) for a few minutes. It will probably go out of tune.
- Adjust the tuning, then keep playing and adjusting, using the tuner to ensure that overall the instrument does not drift sharp or flat.
- After a time the tuning should settle down, providing environmental conditions remain constant (no changes in temperature, humidity or air pressure). On stage, or in a session in a pub this will not necessarily be the case. Now you know why the mandolin player in a bluegrass band is always touching up his tuning (off-mike if he has any sensitivity).
Theory and practice
OK, now we'll have a look at factors affecting tuning. There are three main problem areas:
- Your ear
- String tensioning
- Intonation of the instrument
Not a lot to say about this, other than that practice will improve your ear no end. You have to be able to hear slight differences in pitch when you are comparing the tuning of the two strings of a pair. OK, the electronic tuner is a great help, especially to beginners, but you often need to make slight changes, especially when getting a chord to sound right. Here you are listening for harmonies (intervals in pitch) to sound right. There is also the classic situation in a jam session where everybody gradually tunes higher and higher during the evening. (It's no use shouting out, "Please tune to my tuner!")
You need to be aware of how string tension can change even when you don't touch the tuners! There are also all the difficulties involved in getting your strings to respond when you do tension them (i.e. turn the tuners).
Intonation of the instrument
- Movement of the top
The mandolin body is a compressible box. Downward pressure is put on the top by the strings acting through the bridge - the greater the tension on the strings, the greater the pressure on the top. This actually forces the top downwards. The top stabilises in a particular configuration, but environmental changes (e.g. contraction/expansion of the wood due to temperature, pressure and humidity changes) will move the bridge up or down slightly as the top moves. And this will affect the tension in the strings, altering your tuning. A classic case is that of bringing your instrument into a warm pub on a cold day. When you open the case the mandolin is subject to a sudden temperature increase, and goes out of tune. Ditto when you go under the hot lights on stage. (Not only is the wood affected, but the metal parts - strings and tailpiece - will also respond to the temperature change.) Extreme changes in the environment can have dramatic effects. David Grisman once described arriving by air in Switzerland to find the top of his mandolin had dropped so much as to reduce his string action to zero. Less extreme are the environmental changes that take place from one day to the next. You can have you mandolin tuned to concert pitch one day, to find that by the following evening the whole instrument has gone sharp or flat.
- Strings binding
The main frustration of mandolin tuning, particularly with bluegrass instruments, is that the strings always bind in the nut and bridge slots. Here is an example. You decide that one of your strings is very slightly out of tune. You make a fine adjustment at the tuning peg, but the pitch of the string does not change in the slightest. The string is binding, probably in the nut. You turn the tuner a bit more and suddenly the pitch alters dramatically and way too much., as the string suddenly moves in the slot.
The problem can be alleviated to an extent, but is one that you have to live with. Some players prefer to tune up to a note rather than down, believing that the string moves more immediately through the slots when tension is increased rather than decreased. In this method if a string is too sharp you first slacken off enough to detune it and then tune up again to the required pitch. Personally I prefer to adopt a policy of estimating the delayed effect of tuning, like deflection shooting with a gun. When you make a fine adjustment at the tuning peg nothing happens immediately, but as you continue playing the string gradually moves in the nut/bridge and sets at the new tension along its complete length. Another way to approach the problem is to adjust the tuning peg, then pull down hard on the string with your pick to force movement in the nut and bridge slots. This often results in a temporary flattening of the string before it settles back to what you hope is the new, correct pitch. Similarly you can push down on the string between the tuning peg and the nut, which initially sharpens the string before it stabilises.
It follows that it is important to have the nut and bridge slots correctly cut. This is a vital detail that is often overlooked. Briefly, it means that each string should sit snugly (but not too tightly) in its slot. The bottom of the slot should be U shaped, not V shaped or rectangular in cross section. The slot should be neither too deep, too shallow, too narrow, too wide nor too long. Here we are moving into the realm of setup. Personally I have no lutherie skills and I leave this to a good repair man (not just any old woodworker who will have a go at the slots with a fretsaw). It is quite a skilled operation - to see what is involved, check out the relevant pages on nuts at Frets.com
Many players use graphite to lubricate the nut and bridge slots. A common technique is to use soft pencil lead. You have to keep the pencil point sharp to reach the bottom of the narrowest slots. Use the softest pencil you can buy and try to get as much lead into the slot as you can. However, I have been told that some pencils have so much binding material added to the graphite "lead" that this actually creates extra friction. I think the jury is still out on this one.
Thanks to Geoff Blyth for the following tip: "I have a bottle of CK Dry Powder Graphite which I bought at a local hardware store, which is magic if the strings are binding in the nut. You have to be a bit careful how you apply it or you get black fingers. However it does the trick and it doesn't have any binding agents as it is specifically formulated as a lubricant."
A nut made of very hard material (like bone) is less likely to bind than the softer plastic usually used in cheaper mandolins. Delrin is a very low friction material, but seems to be too soft for mandolin nuts, as the strings dig into it.
Greater bridge height and steeper backward rake of the peghead are factors that can cause strings to bind. Have a look at the picture of the peghead angle of a 1924 Gibson A4 at Frets.com (the picture at the top of the page). These features are conducive to better tone and volume, and they are generally found in the better quality mandolins used for bluegrass, but the downside is that they make it more difficult to tune. The heavier gauge strings used for bluegrass playing are also more likely to bind, owing to their higher tension. However, if you play a folk-style mandolin with a lower bridge, flatter peghead angle and lighter gauge strings you may wonder what all the fuss is about.
- Strings jumping the nut and bridge
This is the opposite of binding. When you play a mandolin hard, e.g. on stage or in a noisy jam session, the pick pressure may cause one or both strings of a pair to move in the nut or bridge slot and go out of tune. Again, adjustment is required. You have to work out which string has gone out of tune - or maybe they both have!
- Tuning gears
Newcomers to mandolin playing often think that a lack of response in the string when the tuning peg is turned is due to worn gears. With a newer mandolin this is probably not the case, though it is more common in older instruments. However, binding of the strings is more likely to be the culprit. You can replace tuners - good quality tuning gears are nice to use, but you will still have problems if the strings are sticking excessively in their slots.
It does no harm to apply a few drops of oil to the tuner gears and bearings every few months. Do it when you have removed the string to change it, so you can turn the tuner mechanism easily and get the oil worked in.
Good intonation is what a piano tuner aims for. If he does his job properly, all the notes sound 'in tune'. However, whereas each note can be tuned separately on the piano, a fretted instrument relies on an accurate fretboard.
The tempered scale used on all instruments is a compromise. Put briefly, this means that all the individual notes are slightly out of tune, with the result that every scale in each key sounds more or less in tune. The Musical Instrument Makers Forum has links to fret distance calculators, on-line and downloadable - scroll about one third of the way down their page. If your fretboard is inaccurately fretted you will not be able to play in tune all over the neck. Worn frets can also cause notes to be out of tune. A good professional luthier can check the intonation of each fret electronically.
- Bridge position and compensation
On a short scale instrument like the mandolin a compensated bridge is a necessity. This is because the standard fretting creates different results on each string, the differences being magnified by the short scale length. I'm not an engineer or a physicist, but what it amounts to is this. Stopping the string half way along its length raises the pitch an octave - in theory. The halfway point is the 12th fret, and the bridge is positioned so that the note at the 12th fret is an octave above the note of the open string. Jim Coon has written a useful page about finding this half way point, using harmonics. If you used a straight bridge positioned so that the note on the 1st (E) string stopped at the 12th fret was the exact octave above the open string, the other strings would fret sharp to varying degrees. On longer scale instruments like the guitar and banjo it can be enough to angle the bridge backwards on the bass side, but the mandolin requires individual compensation for each string. Frets.com has detailed info on calculating compensation (for guitars - but the principles apply equally to mandolin).
What the luthier does is to cut a ramp backwards into the bridge saddle, theoretically to the point where the string sounds exactly an octave higher at the 12th fret. The result is that the 1st string is the shortest from nut to bridge, followed in order by the 3rd, 2nd and 4th strings. Perfect intonation at the 12th fret can be achieved if the saddle is quite thick, front to back, as the difference between the 1st and 4th string compensations is considerable. Mandolins for folk music often have such thick compensated bridges (usually one-piece), but the tone and volume of a bluegrass mandolin is usually thought to be improved by a comparatively thin bridge. And, you've guessed it, the bridge is not always deep enough, front to back, for complete compensation. Moreover, a lot of people (most?) purchase a bridge in which the compensation has been pre-cut in a standardised way, without reference to their own particular instrument. Accurate compensation is specific to the string diameters and tensions, and also a particular bridge height (action). If you change to a different string set or alter the action the compensation requirements change. You may find that all the strings fret sharper or flatter, and that the bridge will have to be moved backwards or forwards. Check intonation whenever you change to a heavier or lighter gauge of string or when you raise/lower the action. Retuning strings to a different pitch will also affect intonation. This is why it is difficult to obtain good intonation with cross-tuning, where one string of a pair is at a different pitch (and therefore tension) from the other. (It is even more of a problem on the 12-string guitar, with its octave stringing.)
If you have purchased a mandolin and find you have intonation problems, it is always worth checking that the saddle is on the right way round! (I know a purchaser of a vintage Gibson F5 who had this problem!)
Mandolin Notebook, Vol 1 No 2 carried an article by Jim Hale on making a compensated saddle. This issue of MN is still available at Elderly Instruments. The CoMando FAQ page has some useful info on mandolin bridges - see section 5.3 and the following sections.
Positioning your bridge, even a compensated one, is usually a matter of compromise on a bluegrass mandolin. You have to balance one string fretting slightly sharp against another fretting slightly flat. Personally I have to put up with a first string which frets progressively flatter as I go up the neck. On longer notes I even compensate by pushing the string to one side with the fretting finger, to sharpen it.
- Compensated nut
Guitar and banjo makers have looked at the alternative of a compensated nut, though I've never heard of one on a mandolin. Have a look at Stephen Delft's page about compensated guitar nuts - a very full and thoughtful article with pics (including a compensated nut for 12-string guitar, to allow for the different compensations required by a pair of strings an octave apart).
- Saddle tilt
A further problem is created for the users of two-piece bridges by the tendency of the saddle (the top bit) to tilt forward under string tension. This will obviously affect intonation (and maybe tone and volume), and needs to be corrected. Lower the string tension until you can tweak the saddle back to the vertical position by applying gentle backward pressure by hand. Pull backwards, but avoid any downward force on to the top of the instrument! The best time to make this adjustment is when you do a complete string change. Detune all the strings, but keep enough tension to hold the bridge in position. Change each string in turn, lightly tensioning them to keep the bridge in place. When you have changed all the strings, tweak the saddle into the upright position, tension the strings a bit further and pull the saddle back again. Keep repeating the process until there is too much string tension for you to be able to move the saddle easily. By this stage the saddle should be retaining its vertical orientation in any case.
I don't recommend trying to tweak the saddle backwards under full string tension. I have seen Mike Vanden, a world-class luthier, do this - he grinned and said it's OK if you know what you are doing. However, for the amateur there is too much risk of the whole bridge slipping and causing damage to the top of the instrument. I've also seen a suggestion that you can tweak the saddle upright under full string tension by gripping it with a pair of pliers - rather you than me!
Many players recommend the Brekke two-piece bridge. This has a unique design which lessens the tilting effect. It may also alter the tone of your instrument, for better or worse - you are the ultimate judge of this!
Modern strings are a miracle of technology. They are created to exacting specifications, including precise diameters. A brand new string of good quality should have uniform diameter, winding and plating thickness along its length. Change any of these factors and nasty overtones will, not surprisingly, creep in. This makes it more difficult to tune the string and provide good intonation all the way up the fretboard. Old strings can be virtually impossible to tune. The surface becomes pitted with corrosion, covered with grease deposits and worn flat through contact with the frets. There are two morals: change your strings regularly and rub them down with a cloth (cotton is good), on top and underneath. While you have the cloth under the strings, you should also pass it over the fretboard to remove sweat and grease which would otherwise cause fret corrosion or soak into the fingerboard.
Occasionally you may change a pair of strings and find it impossible to get the new ones to fret in unison. This is because of an imperfection in one of the strings which has somehow got past the manufacturer's quality control system. Maybe there is a variation in diameter or some plating is not quite uniform. Corrosion of the surface might be a factor in a string that has been stored for a long time in damp conditions. You can try replacing just one string to see if this solves the problem, but you may end up chucking both strings and starting again with a fresh pair.
How often to change strings? Professionals change them every day, perhaps even more frequently. If you have the time and can afford to do so, follow their example. For an average amateur once every week or two would be ideal. Personally I leave it much too long between string changes! I'm usually prompted after a month or two by - of course - tuning problems, poor intonation and lack of volume and tone.
Go to the Frets.com page on restringing your mandolin for details of how to change strings.
There is an excellent page on tuning at Mandolin Cafe. The Frets.com site is well worth a browse on general mandolin setup. A good start is the mandolin owner's manual. Also check the page list for the Frets.com site. The Fret Not mandolin repair page (at a different and smaller site) is also worth a look.
I hope this survey has gone some way to explaining why the mandolin is a difficult instrument to tune. With practice, you will overcome the problems satisfactorily, but it does take time, thought - and careful listening!