Sterner TMPreserving Tone & Tuning


Placing a capo on an instrument is a very delicate thing and should be done with great care. Too many musicians are unaware of this, resulting in 1) muffled tone or 2) bad tuning. These two conflict with each other and the quest is to find the optimal compromise. On stage there is no time to retune. Lets take a closer look on how a capo works:
Preserving tone.
This placement behind the fret, bend the strings over the fret. The strings are pressed down against the fret all the time - even when they vibrate. This makes the fret work as a nut. The tone is preserved, but the tuning suffers since the strings are bent. The farther away from the fret you place the capo, the more you have to bend the strings to prevent them from buzzing against the fret.
Preserving tuning.
Line up the edge of the capo along the top of the fret. The fret itself and the stiffness of the strings will prevent the capo from bending the strings. The tuning is preserved, but instead the strings are pressed into the soft pad resulting in muffled tone.
Preserving both tone and tuning.
Tighten the capo harder. Hard enough to bend the strings just a little over the fret. This will preserve both tone and tuning. As the strings dig into the pad, the edge of the pad will be stopped by the fret. This prevents the capo from being pressed down too far.


Three special capos were designed with this insight. Unfortunately these capos did not make it commercially. Maybe they were too extreme?
  • Hamilton Fretspanner has a very wide bar to prevent the strings from beeing pressed down between the frets.
  • Sabine has two attachments on the bar to guide the capo when placing it against the top of the fret.
  • Baldy Brothers has a bone edge on the bar to preserve the tone. It was intended to be placed in the position shown in the second figure above.



The capo should bend the strings over the fret
- but as little as possible.

In other words:
The strings must be bent enough to always press against the fret. Try to do this as close to the top of the fret as possible. This is achieved by placing the edge of the capo along the top of the fret and tightening the capo hard enough.
To facilitate this the capo should have a pretty hard, thin pad on the underside of the bar giving it a distinct edge. A thin bar concentrates the pressure area closer to the fret. Make sure the curve of the bar corresponds to the curve described by the top of the strings when they are pressed down to the fret. That curve is straighter than the radius of the frets.
Light gauge strings are more sensitive than heavy strings. They require less pressure.
Find a balanced set of strings in that respect that the gauges decrease from heavy to thin in as equal steps as possible. This equalizes the capo pressure on the strings.
Keep your frets in shape. If your frets are worn you have to place the capo further away from the fret, resulting in tuning problems.