Tuesday, July 14, 2009

Manipulating Tuning on Fretted Instruments in Real-Time

One of the most difficult things about playing a fretted instrument, especially in an ensemble, is tuning. Due to a variety of factors-- such as a relatively fixed scale length, fixed fret placement, and non-uniform metal-string inharmonicity--even a well-set up fretted instrument will always be, at best, only vaguely close to in-tune over its entire range with respect to twelve-tone equal temperament. Discrepancies of up to ± 4-10 cents are common even in the best of cases.

There are various systems and modifications, including the Earvana™ nut and the Buzz Feiten Tuning System™, which aim to get the guitar closer to the equal-tempered ideal. There are even guitars with bent frets aimed at correcting the problem. However, even if you found a guitar that would be 100% in equal-tempered tuning over the entire fretboard, there would still be times when you would want to pull certain notes one direction or another to tune them with the other instruments in the ensemble. Often when instrumentalists tune chords and ensemble passages, they will gravitate toward just, or resonance/overtone-based, tuning of the chords. In other words, especially with more harmonically complex chords and structures, even perfect equal temperament wouldn't quite get you there, in some situations.

Fortunately, there are many things a fretted instrumentalist can do to manipulate tuning in real-time. Good tuning is a part of good listening and good technique, and NOT exclusively a part of good setup/maintenance. In other words, tuning doesn't stop when you've finished twisting the pegs until all the green lights come on-- it is only beginning.

When tuning, as with most other aspects of musicality, the most important thing is to listen. If you learn to relish good tuning and to make tuning a priority, much of the rest will take care of itself. Good tuning, in a majority of musical situations, is so preferable to the alternative that the ear, and the hands, will find a way to make it a reality. However, there are a few things I consistently find myself doing, in almost every performance, to improve and enhance the tuning--and therefore the sound of the ensemble. I figured it would be worth it to touch on a few of those here.

To raise pitch:

There are, fortunately, many ways to raise pitch a few cents. I am ignoring the obvious ones-- like pulling back on a vibrato arm or twisting a tuning key-- in favor of the ones that are most useful in real-time performance.

  • Bend the string slightly in either direction. This one is the most obvious, and also the most easily implemented. The fact that you can tune individual notes in chords this way is advantageous.
  • Bend the neck slightly backward, as if to create a backbow in the neck. This works well on open strings and relatively well on entire chords. You can simply exert backward pressure with the fretting hand, or you can grab the headstock with the picking hand. Obviuously, you will want to be careful with this maneuver, but within reason it's safe for your instrument.
  • Exert pressure on a string behind the bridge or nut with the picking hand. This one typically has few advantages over one of the methods listed above, but can be useful in certain circumstances or for a special effect. If one note in a chord needs to be raised by a fairly large amount, this can be a good choice to avoid collisions by simple bending.
  • On an instrument with a floating vibrato, exert pressure on the bridge with the palm of the fretting hand. This one can sometimes be harder control. It could likely be mastered with practice.
To lower pitch:

While raising pitch is fairly easy, lowering pitch is quite another matter. I have found only two practical ways to lower pitch of a tone in real-time without use of the tuning keys or vibrato arm, which, in most cases, is impractical.

  • Bend the neck slightly forward, as if to create an upbow in the neck. The same tips and cautions apply to this method as apply to its analog in the "to raise pitch" section above. Disadvantages, apart from possible strain on the instrument, include an inability to tune individual notes in a chord.
  • Compress the sounding length of the string using a stiff backward motion of the fretting finger. To accomplish this maneuver, you are basically jamming your fretting finger into the fret in a motion that moves the finger toward the bridge of the instrument. Imagine that you are stretching the length of the string between your finger and the nut, and therefore slackening the string a bit between your finger and the bridge--which, of course, is exactly what you are doing. The object is to decrease tension on the sounding length of the string (i.e., the length between the fret depressed and the bridge) a little bit. Consequently, the more rigid the string material and the higher the tension on the string, the less you will be able to alter tuning in this manner. It works particularly well on nylon- or gut-stringed instruments, but can still be used to some effect on steel-string guitars and basses. On steel-string guitars, it tends to work more easily on the wound strings than on the plain strings. The greater the strength of the motion of the fretting finger toward the bridge, the more the sounding length of the string will be slackened, and the greater the drop in pitch. With practice, it can be perfected to allow the player to tune individual notes within chords.
So there are a few techniques to experiment with to help hone your real-time tuning and intonation. It bears repeating that intonation is not a one-time adjustment on an instrument, but is rather the art or practice of real-time tuning adjustment during the course of performance. A fretted instrument may not have the ease nor range of tuning manipulation that, say, a violin might-- but its tuning is equally far from the fixed nature of a keyboard instrument. A skilled guitarist or electric bassist can, with a bit of care and listening, create beautifully tuned unisons and harmonies with other soloists.


  1. Nice tips. Here are a couple of mine. You can also pay attention to how hard you fret - a heavy touch can raise pitch by pressing the string a little below the fret height.

    Also, when I do tune the guitar I leave the g string a hair flat. For many voicings this works better. The g is also usually a slinkier gauge and easier to raise a bit if needed by bending.

    From playing in a brass quintet, knowing if a note is acting as the third of a chord can help tune it to the key/chord. The third of a minor chord should be a little flatter. A major chord's third a little sharper.

  2. John, good tips. I agree with all.

    Which brings up the point of fret height-- lots of guitarists like very tall frets, but they can actually act a bit like a scalloped fretboard unless your touch is suitably light.

    Tuning the G string a hair flat makes good sense for certain things. For many standard gauged sets, I believe it has more pounds of tension on it than any of the other strings, so its inharmonicity is greater. It can often be several cents sharp in certain areas, particularly the first five frets.

    Certain open-position "cowboy" chords, especially, (E, A, F) can benefit from a slight flattening of the G string tuning. Actually, almost any chord form in the first position that doesn't use an open G string will benefit from it. Higher up the neck, the compromise becomes more apparent.

  3. I got the g string tip rom Richard Lloyd a while back.