Whether you are a beginner or an accomplishing musician, tuning a guitar is the most important procedure a guitar player must perform before playing even a single note, and this needs be done each time the instrument is picked up. Temperature, humidity, the stretching of strings and other factors affect tuning. Strings will also slip up or down at any time, and can cause much havoc during a live performance, where time to retune is nonexistent.
There are several ways to tune a guitar, and available tools include pitch pipes, optical strobe tuners and electronic tuners ranging in price from $10 pocket-sized chromatic tuners to $200 rack mounted digital units. All guitarists should own a reliable tuner, but it is important to realize that these devices can never create what we call “the quality of intonation”. This is rather an artistic product which requires much knowledge and experience.
Students are often taught to tune their guitar by playing the 5th fret on the E string as a reference for the A string. Similarly, the 5th fret on the A string is used for tuning the D string, the 5th fret on the D string as a reference for the G string, then the 4th fret on the G string for B, and back to the 5th fret for the high E string. Of course, this assumes the sixth string (low E) is in tune, and a slight error in tuning any of these strings replicates down the line so that by the time you get to tuning the high E string, your reference note could be appreciably out of tune with respect to the low E string.
Tuning to a standard instrument, such as a piano, is important if you are playing with other musicians. But, even if you are just playing by yourself, it will help develop your ear if your guitar is in standard tune.
Here’s another method to tune up. Purchase a tuning fork; we use an A (440 Hertz) fork, which is a standard frequency. Tuning forks are inexpensive, and available at many music stores.
Hit the tuning fork on your knee, not on the guitar or other hard surface to prevent damage to it. Hold the tuning fork’s handle against the guitar’s body, where it will be amplified, and use this note as a reference to tune the A string. The harmonic produced at the twelfth fret of the A string is 440 Hz (the fretted note at the twelfth fret is also 440 Hz). Tune this note to the tuning fork (the open A string is actually 220 Hz).
Once that string is in tune, we can use “natural harmonics” to tune the other six strings. A harmonic is a higher pitched, bell-like note that can be produced from a string by lightly holding your finger directly over top of key frets along the string, plucking the string hard and then quickly removing your finger. Unlike playing a normal note where you place your finger slightly behind a fret and press down with the tip of your finger, here we place the fleshy part of a finger over top of a fret. If you are not familiar with getting a harmonic sound out of your guitar, start by practicing on the twelfth fret on each of the six strings, and use the fleshy part (not the tip) or your ring finger. The twelfth fret is positioned at the middle point of the vibrating part of the string, and the harmonic produced will be a note one octave higher than the open string.
By using harmonics, we can listen for “beat frequencies” to aid in tuning. A beat frequency is a periodic volume change produced by two frequencies (one from each string) being slightly out of tune. If the two notes are almost in unison, the pitch may sound about the same, but a tremolo effect will be heard, with the volume varying up and down. As the two vibrating strings approach the same frequency, the fluctuating volume (“beating”) will slow in speed, and will disappear completely when unison is reached. This beating of out-of-tune frequencies is one of the most important tools we have for tuning. Throughout history, musicians have long sought a definition of what is “in tune,” or how the notes harmonize with one another in consonance. The harmonics of a vibrating string remain one of the most stable and realistic definitions we have for what is truly “in tune”. The harmonics of a vibrating string will not beat amongst themselves; they are therefore, in “agreement” or in perfect harmony with one another.
Each vibrating string produces the harmonics of a major triad. For example, and open A string produces the harmonics A, C# and E. The octave (A natural) and the fifth (E natural) remain the best definition we have of what is “in tune” and can be relied upon as tuning references. We can now create a goal for ourselves to tune an A chord where all of the As and Es agree with one another.
We can create a “perfect fourth” by matching the harmonic of the A string at the seventh fret (which is E) to the harmonic produced at the fifth fret of the low E string, which is also E. The interval from A DOWN to E is called a “perfect fourth” ; the interval from an A UP to an E is a fifth. Central to the idea of guitar tuning is the concept of “consonance,” or the pure tuning of an interval. The most fundamental consonant intervals a guitarist should attempt to master are the perfect fourth, fifth and octave. With these, an entire world of pure tuning can emerge.
We now have the A and low E string in tune. Let’s also use an A Minor chord in the first position to aid us with this harmonic tuning. The harmonic at the seventh fret of the A string is E, and it will equal the frequency of the open high E string. We’ve now tuned a perfect fifth.
The fretted E note on the second fret of the D string can be tuned perfectly to the harmonic at the seventh fret of the open A string. This interval is also a perfect fifth.
The A note on the second fret of the G string can be tuned to equal the harmonic at the twelfth fret of the open A string; this is an octave.
The B string should be tuned in reference to either the high or low E string. The C (on the B string) in the A Minor chord is not a bad interval in the scheme of tempered tuning, but it cannot be matched to any harmonic at this point. Let’s assume we are happy with our tuning of the low E string. The harmonic at the seventh fret of the low E string can be used as a reference to tune the open B for a pure perfect fifth. You can also match the harmonic at the seventh fret of the open high E with the harmonic at the fifth fret of the open B, and tune a perfect fourth.
We can now play an in-tune A Minor chord. All of the Es we play should “agree” with the E harmonic located on the seventh fret of the A string. All the notes will be either A or E, with the exception of the C on the B string. As you learn to locate and hear harmonics, your tuning will become more and more accurate. You will also notice that these harmonics exist in every chord and note you play on the guitar.
Here’s an interesting and disturbing phenomenon to experiment with: Tune the A string using a tuning fork. Now tune the E note on the 5th fret of the B string to the E harmonic located at the seventh fret of the A string. Play an A Major chord in the first position. When you match the C# on the B string with the C# harmonic on the A string (at the fourth fret) you will hear how radically thirds are out of tune in the tempered tuning system, and that there is nothing that can be done about it. All major thirds, on all pianos and guitars, are radically sharp, and they cannot be flattened without disturbing the entire system of equal temperament.
For instance, let’s pursue a goal of tuning an open E major chord using all of the E and B harmonics we can locate. When we play the final open E, we can see that all of the notes are either E, B, or G#. In this chord, we have three E notes, and all of them are producing a G# harmonic. This G# harmonic can never be in tune with the fretted note of the chord, and must be accepted by the player with his or her “relative pitch” ear. Welcome to the world of tempered tuning!
The more advanced reader will realize that this prescription for tuning uses pure Pythagorean relationships, which ultimately must be abandoned in order to play in all keys in favor of equal temperament. The guitar is very much a “key colored” instrumen,; that is, certain keys will be favored over others. Learning to tune purely is, in our view, the first skill to cultivate. Later, the problems of tempered tuning can be brought to bare on the guitar. Learning to hear and tune intervals is one of the most important elements in creating your own sound on the guitar, and is a means of having your own identity as an artist.