How To Tune A Guitar
September 7, 2008 by Lee
Unless you have never played a guitar before then the subject of tuning is quite obvious and straightforward. You plug in your guitar tuner, turn the machine heads until the needle is centred for each string in turn and your done, right?.. Well actually, no.. not quite!
There’s more to tuning a guitar than just plugging in a tuner and checking all six open strings.
I’m not going to waste time talking about obvious stuff like how to use a guitar tuner or how to turn the machine heads (tuning pegs) to adjust the string tension. What I am going to talk about here are some common guitar tuning methods but most importantly, tuning problems you are likely to encounter and how to get around them.
Tuning the guitar the old fashioned way
Before the electronic tuners came along there were three main methods used to tune a guitar.
- Use a piano for reference on all six notes
- Use a pitch pipe for reference on all six notes
- Use a tuning fork for reference on just one note
The first two are straightforward enough. Play the E, A, D, G, B and E notes on the piano or the pitch pipes and tune the guitar strings to match.
Method number three, using a tuning fork is a little harder. The most common tuning fork is set at 440hz which is the same pitch as the ‘A’ note on the guitar’s thin E string at the fifth fret. This gives you only one note to work with so you need to tune the rest of the strings in relation to each other.
Most of you will already know this but for those that don’t, here is the most common method for tuning a guitar from only one reference note. First, you can use the tuning fork to tune the ‘A’ on the thick string at the fifth fret. You then tune each string in turn by matching the pitch from the string below it. For example.. once you have the sixth string in tune you can then play it at the fifth fret while playing the fifth string open. In other words, tune the open fifth string to match the pitch of the sixth string, fifth fret. Once that is done you then move to the next string pair… Play the ‘D’ at the fifth fret fifth string and tune the open fourth string to match the pitch. Use the diagram below to do this for each string until all six strings are in tune.
This method is okay but it does present a problem. Unless you can manage to tune each string perfectly then it’s likely that by the time you reach the thin E string, it probably won’t be in perfect tune and there will be a noticeable pitch difference between the ‘thin E’ first string and the ‘thick E’ sixth string, apart from the obvious difference in octaves.
There are two reasons this happens. The first is, your hearing might not be accurate enough and the very small inaccuracy that may occur between the tuning of the fifth and sixth strings become a larger, more noticeable error by the time you get to the second and first strings. Secondly, the intonation on a guitar (more on this in a moment) is never perfect and the worse this is, the harder it is to tune the guitar, with or without an electronic tuner.
Although with a little experience and a decent guitar it’s possible to get a perfectly acceptable tuning accuracy using this method, it’s a better option to even out and average the tuning across the fretboard by combining a few tuning methods together. First, lets take a look at another common method, tuning with harmonics.
Tuning the guitar with harmonics
There are two advantages to using harmonics to tune the guitar and one disadvantage that I can think of.
- Easier to hear the BFO with harmonics as opposed to fretted notes
- Using harmonics leaves your hands free to take care of tuning while both notes are still ringing
1. Takes no account of guitar intonation.
First lets get a little bit technical for just a moment. What is BFO?
BFO is an abbreviation for Beat Frequency Oscillation. In short, what this means is this. If you have two tones of different pitches playing simultaneously, then a third ‘virtual’ pitch is created which is the result of the difference in frequency of the two other pitches. I use the word ‘virtual’ because I can’t think of a better way to describe it but the third pitch is however, very much a real entity, it certainly exists, it’s just that you didn’t create it yourself.
I get a feeling this might not make much sense if you aren’t technical minded so lets look at an example.
The diagram below shows the three frets where you get the strongest harmonics. Octaves aside, the seventh and twelfth fret harmonics will produce the same notes as you would get if you played the same notes fretted. The fifth fret harmonics will produce the same note as the open string.
Harmonic notes at fifth, seventh and twelfth frets.
Take a listen to the audio sample to hear the BFO in action.
I use heavy gain and distortion on the first part in this sample as it gives more sustain and also makes the BFO stand out even more. It is then followed by the same thing with a cleaner tone.
What you hear first is the harmonic plucked at the fifth fret, fifth string followed by the seventh fret, fourth string. At first they are in tune and then as I slightly detune the fourth string, you can hear the BFO kick in to produce a pulsing sound. The more I detune the fourth string the faster it gets. What you are hearing is the difference between the two frequencies. If the two strings are tuned two hertz apart then the resulting BFO would be pulsing two times per second and so on.
The idea of tuning the guitar with harmonics is to tune the strings until this pulsing disappears. The following audio sample demonstrates this, tune the string until the ‘beat’ disappears and the strings will be in tune. Again, the sample starts with distortion and then a clean version.
Harmonic notes used in samples
There are many ways to use harmonics, fretted notes or a mixture of the two to tune a guitar. There’s no real point in showing a thousand combinations but here’s one method you could use.
The bottom line is there are many notes repeated across the fretboard and you can use any of them to aid with guitar tuning. For instance, between the open strings and the twelfth fret there are seven A’s. You can use any one of them as a reference to tune an ‘A’ on another string, providing of course the first one is already tuned to correct pitch. Even though they won’t all be in the same octave, a little amount of experience is all it takes to get used to hearing and detecting tuning differences between the same note in different octaves. You can of course go past the twelfth fret and find even more of the same note.
Realising this becomes useful for when you are averaging out the tuning across the neck. To understand why you would want to do this requires an understanding of a problem that arises with tuning fretted instruments with more than one string.
The guitar tuning problem
Fretted instruments, such as the guitar, suffer a minor drawback when it comes to trying to get them evenly tuned. Even the most expensive guitar cannot be tuned perfectly along the whole neck because it’s design makes it impossible. While a good guitar can keep tuning inconsistencies to a minimum and hardly noticeable, cheap and badly maintained guitars sometimes have very noticeable tuning problems.
Without getting technical, the reason the guitar cannot be perfectly tuned is because fret spacing is calculated using a set formula which is based on scale length and one theoretically perfect string. Unfortunately, scale length is the only constant used in the formula, but in the real world there are many variables that can affect the ideal fret spacing. String gauge, material type, temperature, tension and height among other factors all need to be taken into account to get the ideal fret placement on the neck. Unfortunately this means the fret spacing would need to be different for every string and this isn’t very practical (even though it has been done) so an acceptable average is what we end up with.
Intonation has a few meanings but when talking about guitar tuning, we are referring to the pitch accuracy with respect to the fret placement. As described above, we encounter a few technical problems with the design of fretted instruments. The thick E string will behave slightly different from the thin E string because of their physical size differences, especially when being stretched by the fretting hand pressing down on them. Because the frets are in a fixed position, it’s possible to get a better “average tuning” across the neck by giving each string a slightly different scale length. Ever wondered why the saddle is set at a slight angle on an acoustic guitar?. Well now you know!.
On most electric guitars the intonation is adjustable via small screws at the bridge. Many amateurs are either unaware of this or sometimes just unsure how to set them up. If these aren’t set correctly then you get all sorts of tuning problems so it’s important to check these are set properly. It’s very simple to do. The best method is with the aid of an electronic tuner but can also be done by ear.
To set the intonation of each string you just need to compare the pitch of the 12th fret harmonic and then the twelfth fret, fretted as normal. If these are different then you adjust the screw (which alters the scale length) until they match. This isn’t hard to do but can be a bit time consuming at first because as you turn the screw, you alter the string tension which changes the pitch, which changes the result. If that doesn’t make sense then don’t worry about it, as soon as you try it out, you’ll see what I mean.
Note also that old strings can cause intonation problems. It’s sometimes very difficult trying to tune a guitar well with old strings even when the intonation is setup ok.
Tuning the strings evenly across the neck
Now down to the nitty gritty. You have a half reasonable guitar, good strings and the intonation is setup correctly. With all these things in place, the guitar probably still needs to be tuned evenly across the neck. If you are lucky and have a real good guitar then this might not be something you need to pay much attention to but just be aware that every guitar will have tuning inconsistencies as you move along the fretboard.
Every time you tune a guitar, with or without an electronic tuner, you should check not just the open strings but also a few other places along the neck as well. If they are noticeably different, then you have to compromise and tune them to an average, or place more importance on the area of the neck you will be playing most.
When I tune a guitar, I usually check the pitch at the open position, fifth fret, twelfth fret and maybe the seventeenth fret for an electric guitar and go for an average on each string if necessary. There is no rule, it’s purely down to what you hear and what you are playing. If you don’t hear anything that bothers you then it doesn’t matter. If you spend most of your time playing past the twelfth fret then let that part of the neck be the priority area for tuning, if you spend most time playing open chords then tune the open strings as priority, or whatever you feel is right for the moment.
The following series of diagrams gives some idea of how you might go about checking the average tuning. There are countless amounts of cross referencing you can do, these are just some of my own preferred tuning checks in no particular order.
Red notes are harmonics and yellow notes are fretted or open strings.
Various Tuning Possibilities..