voicing VI

The final part of my article about harpsichord plectra

Things To Observe

I have mentioned this before: to achieve good voicing results, especially with quill, a positive attitude towards the work is absolutely necessary. If you tend to see voicing and harpsichord maintenance as a hassle, quill is not for you, even if many people exaggerate the problems connected with this material. If you have very little time available for maintaining your harpsichord, you are probably better off with delrin as well.

It is a good investment of one’s time to learn from the start how to give a smooth finish to one’s plectra. Most of the time, a newly inserted plectrum needs to be made somewhat thinner in order to sound good. One always only takes away material from under the plectrum. I use a standard-size woodcarving knife for this task which I keep very sharp (an instruction for sharpening, albeit for kitchen knives, can be found here). It is to a large degree a matter of taste whether one cuts the material or scrapes it thinner. When scraping, one must take care to avoid forming a wavy surface. This is achieved by occasionally changing the scraping angle. Cutting goes faster but the direction of the cut is difficult to control (especially in delrin). I have seen many people who tried to make one plectrum but ended up making three, because of their misdirected carving efforts (it is actually not a good idea to get all angry and frustrated when you have a sharp knife in your hand).

The first step in finishing off a plectrum is to check whether it is stiffer in one area than in another. I do this by manually bending the plectrum; it should bend in an even curve. I only take away material under the area that bends least of all. This is the fastest way to a good-sounding result, and it also creates a shape that is more durable, because the material gets more evenly stressed.

Voicing whole registers requires quite some experience. The most prominent danger when revoicing larger areas is that one loses one’s sound-reference and gets gradually louder or softer. Another danger is voicing each tone individually. If some areas of the instrument sound better than others, this would mean that they end up overpowering the weaker sections. This problem is, for example, typical for the ubiquitous five-octave mid-18th century French harpsichords, where the bass can be loud and sonorous while the tenor is often rather weaker. In situations like this it is necessary to find a voicing compromise that makes musical sense.

Non-structural problems

One of the things plectra like to do (doubtless with the objective of driving the harpsichordist who desperately needs to practice out of her or his wits), is to get hung on the string when returning (see also part II of this article). Most of the time, the reason for this is that the tip of the plectrum is rough (alternatively, the spring or bristle that keeps the tongue in place might be too strong). If we are talking about a delrin plectrum, it was probably rough from the beginning. Usually a wiping with forehead grease helps, otherwise one should try to carefully smooth the tip from below by using the glass file or very delicate knife strokes. Good light often helps to identify the cause of the trouble. Quill plectra, on the other hand, can get rough through use. One might need to push them through somewhat further and altogether re-shape their tips.

A typical problem in new harpsichords voiced in quill is that the fresh strings bite into the surface of the plectra and create a groove, which then produces a creaking and very forced tone. After a few months, the surfaces of the strings become slightly polished at the plucking point and the problem will subside. But this initial period of playing-in is sometimes rather trying. One must be prepared to repeatedly rub the top surfaces of the creaking plectra with one’s fingernail and to occasionally apply some forehead grease.


I have experimented with strips of quill that I kept immersed in oil, with plectra that I oiled after voicing and with completely dry plectra. In terms of durability, I have not been able to find much difference between these methods. Some kinds of vegetable oil appear to be bad for the strings as well, or they get sticky after some time. If one wants to apply oil, olive oil seems to be a safe choice. A very little oil on every plectrum is usually more than enough.

Structural problems, or: When Not To Use Quill

Not all kinds of harpsichords are suitable for quill plectra. Sometimes the mortises were designed to accommodate a specific shape of plectrum. Especially those that are higher than the maximal thickness of a strip of quill present a true problem: to jam the plectrum into the mortise so it gets wedged between its sides is ineffective: the plectrum can easily fall out again. In addition, quill plectra are not recommended in the following cases:

1). In harpsichords where the average length of the plectra is shorter than about 3mm. It is much more work to voice such short plectra properly, and they will always have a shorter life span.

2). In harpsichords where the plectra are mounted in the jack tongue at a clearly visible upward angle, instead of almost or completely perpendicular to the jack. I am aware of the fact that this is sometimes the case even in historical harpsichords. I believe that a slight angle can be very helpful: it enables the plectrum to slip back more easily and it guarantees a consistent and safe pluck, as opposed to one where the plectrum begins to slip off the string half-way through the attack. However, any exaggerated angle will cause the plectrum to grind itself into the string instead of plucking, and the resulting wear is many times greater than necessary.

3). In harpsichords that are played by very many different harpsichordists.

4). In harpsichords that are played by people with a very forceful touch.

Delrin and plastic jacks

I have occasionally encountered the problem that delrin plectra tend to slip out of some types of plastic jacks, because there is too little friction inside the mortises. The only way to solve this is to prepare the strip of delrin extra carefully: it should be infinitesimally thicker than the mortise in the jack tongue. The angle of the tapered tip, seen from above, should be as slight as possible. If the angle is steeper, it will inevitably drive the plectrum back out of the mortise. In this manner the plectrum is wedged into the mortise from all sides.

4 Responses to “voicing VI”

  1. calhoun Says:

    Hi – Just lookin’ around. All very good advice. I did have that odd
    experience of the corroded axles in jacks which had been oiled before
    converted to plastic, then kept by the ocean. I think the acid in the
    olive oil worked as a catalyst to speedn corrosion, so I would say
    that it’s wise to use less oil than would be convenient, and to keep
    it on the quill and avoid letting it soak into the tongues!


  2. skowroneck Says:

    Well, if you plan to apply it to moving metal parts, I guess that camellia oil, the stuff that’s used for Japanese tools, is the safer choice. The ‘near the ocean’ comment is very good, thanks, I forgot that. At the time in the Hague, it was my bike that I was worried about…

  3. Saverio Says:

    Thanks for your insructions. Very, very useful, as for instance the round profiles on the tip of the plectra. I’ll try.
    Now I’ve a question about materials.
    My harpsichord (a Ruckers double à grand ravalement) by William Horn (Brescia, Italy, 1994) had at first white delrin plectra, and I was quite satisfied (I had to be).
    Then the builder suggested me to change with (black) celcon. At first it seemed to work fine, with a more precise attack or it was just a feeling), but after a year of work the plectra began to produce a bad tone, mainly in the upper notes (too harsh). Now I decided to change again and to go back to delrin (maintaining feather plectra is a demanding task for me).
    The builder now suggests black delrin, which, he says, is closer to feather quilling than white delrin.
    Do you have suggestions on this?

    Thank you again.


  4. skowroneck Says:

    A little difficult to answer this. First of all, I have no experience with celcon, and especially with the work-hardening curve of this material. If it were Delrin, I’d advise to scrape the plectra that are in the instrument a little thinner and to re-voice them properly. It’s a lot of work to change everything to another material, and even with Delrin, you’d run into the same thing – that the material hardens and needs a second go at some point.
    As to the second question, I personally prefer white Delrin, because I can, with the tools I am using, achieve better results (in shorter time) with it. I find black Delrin somehow unpleasant to work with. It hardens too; in the beginning, it tends to sound too “round” (actually not too close to quill to my taste), but after a year or so it will get much harsher in sound. The problem with all this is that there may be varying qualities of these materials out there that I don’t know, plus that a successful voicing job always relies on the combination of work technique and material. I’m sure that if your maker is confident using a certain material, he will also be best at it.
    Bottom line, I’d try to re-voice what’s in the instrument, and if there is no improvement, I’d probably do what the maker recommends.

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