Become a better musician: Guitar Tuners & Tuning
This article was researched and written by the webmaster of this site and is © 1996
A quick word before we start about two ways you can help yourself to become a better guitarist:
- Use guitar software - such as this one (go for the free trial download)
- Take guitar lessons - this guy's good (it's a 'learn guitar online' package)
If you're a guitarist you'll no doubt remember one of the first things you learnt when you started was how to tune your instrument. And having learnt how to tune to the required notes, using the mnemonic, 'Every Armpit Does Get Body-odour Eventually' (or something like that), you probably thought that was all there was to know about tuning, right? Wrong.
The issue of tuning and intonation is complex, but anybody who calls themselves a musician should know something about it. So here's a crash course.
A common complaint by less experienced guitarists with musical ears is that their instruments, despite being professional models, don't seem to be capable of being perfectly tuned.
We're not talking about incorrect string saddle adjustment at the bridge, use of old, worn out strings, or even frets being wrongly positioned on the neck. We're talking about the fact that, though properly set-up, the guitar never seems to be exactly in tune in all keys. Some chords are in, others appear to be out. Sound familiar? To anyone with good ears it ought to be. So what's going on?
Well, the good news is your ears have not been deceiving you - you can count yourself as a true musician for having spotted the problem.
The bad news is that, due to the inherent limitations of the instrument, there's no such thing as a guitar that's capable of being played exactly in tune in all keys.
To understand why this is, we need to start by climbing into this Pacific Bell phone box and taking a journey back in time, Bill & Ted style (USA link UK link ), to visit an Ancient Greek dude. Most excellent.
It was Pythagoras, back in the sixth century BC, who discovered that a vibrating string stopped at two-thirds and at one half of its length would sound the fifth and the octave respectively of its open note. In others words, there's an exact mathematical ratio between the root and the octave, and between the root and the fifth.
If we now zoom forward to the 17th century, we can observe two more dudes called Wallis and Sauveur finding out the string vibrates, not only as a whole, but also and at the same time as two halves, three thirds, four fourths, etc.
The vibration of the whole length of the string produces the fundamental note, and the vibration in segments produces a series of harmonics, which are present along with, although not as noticeable as, the fundamental.
This discovery provided the explanation for the assertion by Aristotle back in the fourth century BC that a vibrating string, as well as producing the fundamental note, also produces some element of its octave.
Aristotle was not wrong. The vibrating string produces not only its octave as the first harmonic (vibrating as two halves), but also the second harmonic of an octave and a fifth (vibrating as three thirds), the third harmonic of two octaves (as four fourths), the fourth harmonic of two octaves and a major third (as five fifths), and so on.
The point of all this is there's a series of exact mathematical ratios which define pure intervals, all derived from the harmonic series of the open string. The ratio of a perfect fifth, for example, is 3:2. The ratio of a major third is 5:4.
If you don't follow the maths, don't worry - the thing to grasp is simply that any pure interval requires an exact distance in pitch between the two notes.
If we take, say, middle C as a starting point, it's possible to construct a diatonic major scale where, using the mathematical ratios for each interval, each note is exactly in tune in relation to the root note. So the D will be an exact major second above the C, the E will be an exact major third above the C, etc.
However, whilst the notes will be correct in relation to the note they've been calculated from (the C), they won't be correct in any key other than C major. For example, let's take that middle C, and add the F a pure perfect fourth above the C, and also add the G a pure perfect fourth below the C. If we then add a pure perfect fifth above the G and a pure major third above the F, the notes we've just added are a D and an A.
These notes (the D and A) ought to be a perfect fifth apart from each other - but they aren't. They are, in fact, too close together to satisfy the requirement of a fifth interval - that it has a ratio of 3:2. To become a pure fifth, either the D has to be lowered slightly in pitch or the A has to be raised slightly, or a bit of both.
For a really good violin player or singer this is no problem, but on a guitar (or a keyboard), there is only one D and only one A in each octave. A most bogus and sad state of affairs.
Now we come to the subject of temperament. Back in the 17th century each musical key was considered in terms of its own tonality; keyboard instruments would be tuned to 'mean tone' temperament - this meant they would be in tune in the key they were tuned to, but if modulation to another key was attempted the results would be painfully out of tune.
In the 18th century a new system was developed called 'equal temperament', which attempted to mitigate the problem. Equal temperament is they system to which pianos are tuned today, and to which guitars are designed in terms of fret location.
The idea of equal temperament is to average out the differences in pitch between the 12 notes of the chromatic scale so modulation to different keys is possible without pain. In other words, in equal temperament everything is slightly out of tune all the time. The idea is that although everything is slightly out, nothing is badly out in any key.
Now we come to the crunch for guitarists. Given that the instrument is designed to be played this way, it's vitally important for anyone with musical ears to tune the guitar to equal temperament. Many players will tune to a chord (and I've seen this method suggested in many tutor books). This really isn't a good idea at all.
The reason is this: if you have sensitive musical ears, when you tune to a chord your ears will probably want to hear pure or mean tone thirds and fifths. Tune to a D major, for example, and you'll probably find yourself making sure the F# and A are spot on.
But you haven't then tuned to equal temperament, you've tuned to mean tone in D major, with the result that if you try playing any other chord than D major, you'll hear varying degrees of out-of-tuneness.
When soloing, you can of course use microtonal bends to cover for this, to a degree. But play a chord, and problems will start.
So the approach usually has to be to accept that perfect intonation in all keys is simply impossible on a fretted instrument such as a guitar. We have to live with equal temperament. Equal temperament is a system that works - but you do need to make sure you tune your guitar to tempered intervals in order to be able to play it in tune. The guitar is designed to be a tempered instrument, so needs to be tuned that way.
Back to top of page
This article is © 1996, written by the author of this website, and first published in print in the UK 1996. It was licensed to first appear in the UK musician's magazine 'Making Music' (October 1996 issue). Permission has not been given for it to be reproduced anywhere else. All rights reserved.
|
