Pinning the left bridge

Now that the virginal is completely strung, it is time to pin the left bridge. Small metal pins are attached to the inside edges of both bridges to hold the strings in the right place. If the bridges were not pinned, or pinned poorly, some strings would be further from the jacks than other strings, leading to inconsistent voicing since those plectra would have to be longer than the others. Pinning the strings to the bridges also increases the effect of the acoustical function of the bridge; the pins hold the strings tightly against the bridges, helping maximize the transfer of vibration from the strings to the bridges. The bridges then transfer those vibrations to the soundboard, which transfers its vibrations to the air, from the air to our ears, etc.

On the left side of the virginal, the treble hitchpins are down below the level of the bridge. On the right side, the wire is wrapped around the tuning pins so that they leave the pins just a few millimeters above the level of the soundboard. So on both sides of the instrument, the hitchpins and tuning pins hold the strings down against the bridges, increasing the pressure of the strings against the bridges for the aforementioned acoustical reasons. This is called downbearing.

You can also see that the bridge pins pull the strings toward the front of the instrument, quite dramatically in the highest strings. This is called sidebearing and it serves the same acoustical purpose as downbearing.

Moving toward the front of the instrument, the bass hitchpins are set in a higher plane than the treble hitchpins, meaning there is little downbearing; and they also provide little in the way of sidebearing. The theory is that excessive pressure on the bridge by these heavier strings will dampen the vibrating of the bridge and lead to a dull, muffled tone. I have verified this by sounding notes while pressing down with some force on the bridge and listening to the results.
To provide the acoustical benefit of sidebearing without interfering with the free operation of the bridge, these lower strings are backpinned. This simply means that another bridgepin is inserted on the far side of the bridge, offset slightly toward the rear of the instrument. The bass strings are then threaded through the path between these two pins. In this way, the back pins provide a degree of sidebearing, while remaining in mechanical contact with the bridge, reducing the damping effect that would result if a similar amount of sidebearing were introduced by the bass hitchpins.

Although both bridges on the virginal must be pinned, the right bridge was already pinned by the previous owner of the kit; it was about the last task he completed on the project. To locate these right bridge pins, the manufacturer provided cross-marks on the full-sized drawing; the builder simply attaches the drawing to the bridge, and then makes dimples in the bridge with a sharp tool such as an awl. After removing the drawing, each dimple is drilled out and the pins are inserted into the resulting holes.

While this works fine for the right bridge, following the same procedure for the left bridge would require an unrealistic level of accuracy from the manufacturer, draftsman, and builder, so another solution is required. Ideally, a plectrum length of about 1/8" is desired; so, we put a piece of heavy cardstock in the damper slot of a jack, push it back so that exactly 1/8" of the cardstock projects from the jack, and place the jack in the jack guide. We then pull the string that corresponds to that particular slot in the jack guide into position on the left bridge, and make a dimple in the bridge where the string meets the bridge. After all the dimples are made, we drill them all out and insert the pins.



This was a simple and straightforward task. I only ran into two problems; first, the #27 drill bit used to drill out the holes is so small that the chuck in my electric hand-drill could not grip it; I had to use a bit of tape on the end of the bit to give it enough girth for the chuck to hold it in place. This did not work very well, and I had to reposition or replace the tape after every two or three holes drilled. The next time I do this, I will look for a better solution.



The other problem I had was due to my own inexperience and carelessness. The strings are supposed to run just behind the pins on the inside of the bridge, but a couple of times I forgot this and wound up making dimples in the bridge on the wrong side of the string. This is particularly easy to do on the bass strings, which have to be pulled with the fingers toward the back of the instrument to get them into the correct position before the dimple is made.

Anatomy of a Virginal: the Jack

N.B.: I am deeply indebted to Mr. Carey Beebe of Carey Beebe Harpsichords Australia for information and insight concerning modern jacks. At his site can be found his own lucid description of the jack mechanism, as well as many photographs of both modern and traditional jacks.


The jacks perform two crucial roles in the virginal: first, a jack plucks the string when a key is depressed, and second, it damps the string to stop the note when the key is released.

Modern jacks are usually made from molded plastic, although some makers offer traditional jacks in hardwood (at increased cost). Installed in each jack is a tongue, an independent piece which rides on a hinge so that it may rock back and forth. And into each tongue is installed a plectrum, the little strip of thin material that actually plucks the string.

One of the great breakthroughs of instrument design must be the simple yet ingenious design of the harpsichord/virginal jack. The trick is that the tongue must hold the plectrum rigidly in place on the way up when the key is depressed, so that the plectrum plucks the string, causing it to vibrate and produce the sound. But at the conclusion of the note, as the jack comes back down to its resting place, the tongue must allow the plectrum to pivot backwards and slip around the string. If this did not happen, after the initial pluck the plectrum would simply come to rest on top of the string and the jack would have to be reset manually before that note could be played again. In such a case, each note could only be played once in each piece; twelve-tone serial music probably would have evolved much earlier in history.



Fortunately for us, someone (no one knows who) figured out that placing a little stop in front of the tongue keeps the tongue immobilized as the jack rides up, holding the plectrum steady in order to pluck the string. On the way back down, the hinge allows the tongue to pivot back out of the way of the string, and then a small spring (this was traditionally made of brass wire, or more usually, hog bristle) attached to the back of the tongue pops it back into place under the string, ready to pluck again. In real time, this whole operation takes only a tiny fraction of a second, allowing a single note to be repeated quite rapidly.

Nowadays the springs, along with most of the rest of the jack, are normally made of the same plastic (usually Delrin) as the rest of the jack, rescuing many thousands of innocent hogs from the cruel practice of annual depilation.

A small felt damper is inserted into a slot in the top of the jack, with the bottom of the felt positioned just above the level of the plectrum. This felt damps the string, stopping the note when the key is released. Since the plectrum and damper are part of the same mechanism, there is no way to lift all the dampers simultaneously, as with a piano damper pedal, and each note ends as soon as its key is released. In terms of practical musical impact, this means that any "smoothing" or "blending" of one note into the next to achieve a legato effect must be done entirely by the fingers; no cheating with the damper pedal. Sicut erat in principio, et nunc, et semper …

The jack pictured here is not from the Zuckermann virginal kit, but from a French-style harpsichord built from a Hubbard kit. It is a little more sophisticated than the old Zuckermann jack, although the modern touches also create some practical problems. The major differences are the tongue stop, the bottom adjustment screw, and the hinge. In the Zuckermann jack, the hinge is dispensed with altogether and the spring takes over its function. This sounds a bit suspect but it works well enough in practice. We will see how it holds up to constant use once the instrument is completed. As you can see in the photos, the tongue stop in the Hubbard jack is actually the end of a small set screw, which allows the projection of the plectrum to be adjusted. While it is a fine idea to be able to control the plectrum projection so conveniently, it also changes the angle of the plectrum from 90 degrees to a more acute angle, which can adversely affect the voicing. In addition, this raises the height of the plectrum, meaning the string is plucked earlier in the keystroke. Ideally, all of the plectra should pluck their strings at the same point in the stroke - otherwise the response of the instrument becomes inconsistent, undermining the precise rhythmic control which is a hallmark of fine harpsichord playing. Finally, the Hubbard jack includes a bottom adjustment screw, allowing the overall height of the jack to be adjusted. Again, it's a nice convenience, but the small screw heads can dig into the end felt on the key levers, wearing through and making it impossible to remove the keyboard without removing all the jacks first. (Remember, a typical large harpsichord can have 189 or more jacks. Removing and then replacing them all can easily add up to an hour to an otherwise quick operation.) The Zuckermann jacks are supplied slightly too long, and the builder simply files them down until their height is correct. If you go too far and file too much off the bottom, you can always use masking tape or glue some felt to the bottom to raise it again. Historically, jacks never had the bottom adjustment screw; it has been theorized (I believe by Frank Hubbard) that screws with sufficiently fine threads were generally unavailable until the 19th century, well after the "golden age" of harpsichord manufacture (approximately 1500-1800).

A brief video of the harpsichord/virginal action will probably make clear its operation more effectively than any number of words. Here is a clip showing a jack plucking a single note. Since it takes only a tiny fraction of a second, it is difficult to show the tongue pivoting backwards on its hinge to allow the plectrum to go around the string on the way down, so I have included a slow-motion replay of this stage of the action at the end. Choose the High Quality (HQ) setting for better video detail.

Anatomy of a Virginal: The Keyboard

The keyboard of a virginal or harpsichord is independent of the case. The two components are constructed separately and only brought together fairly late in the building process.

To make the keys, or key levers, planks of softwood (basswood is typically used for its lightness and strength, although the choice of wood apparently is not critical) are glued together into a single large board and planed flat. In a small workshop, a template showing all the keys is drawn onto this board and then each key is sawn out by hand or with a bandsaw. In a large production facility, such as a piano factory, specialized gang bandsaws are set up to saw all the keys in one go.

Did you ever look really closely at a keyboard? The geometry is not trivial. The tails of the keys are evenly spaced, twelve to each octave (since there are twelve half-steps in each octave). But in the front, there are seven evenly spaced naturals per octave, with the sharps recessed behind the natural key heads. So each natural key head must be 12/7 of a half-step wide, and everything has to come out even from one octave to the next.

Once fabricated, the keys are placed on a keyboard frame to hold them in position. Smooth iron balance pins are sunk into the balance rail, and provide a pivot for the keys to rock forward and backward on when depressed. The front rail limits how far down the keys can move (this measurement is called key dip), and the back rail supports the backs of the keys when they are at rest.



To obtain the smooth rocking motion of the keys, a small hole, just large enough to fit over the balance pins, is drilled though each key from top to bottom. On the bottom of the key, this hole is left at this size so the the entire key does not slip back and forth, but from the top of the key, the hole is enlarged to permit the balance pin to move freely from front to back as the key pivots. Once cut, it is necessary to use a spare balance pin to burnish the holes in order to achieve a smooth action.



At the back of the keyboard frame is the rack, also called the diapason. This rack consists of a thin hardwood veneer with narrow slots sawn into it, twelve to the octave. Small iron pins are inserted into the ends of each key, and the pins ride up and down in the rack, limiting the side-to-side movement of the keys so that they do not rub against each other when played.

To see some construction photos of a single-manual harpsichord keyboard, visit this site. Be sure to follow the links at the bottom of each post to see the complete process.

Anatomy of a Virginal: the Case

At this point an explanation of the parts of the virginal is in order so that the descriptions of the assembly make sense. The case is essentially a rectangular box, open at the top, with a thin soundboard installed about 2/3 of the way up from the bottom of the case, and an opening in the front where the keyboard goes in. The keyboard is screwed into the case from the bottom, and can be removed fairly easily for service.


In this photo, the case is almost complete, and the strings have been installed. Several pieces are missing from the photo: the keyboard, jacks, jack rail, and lid. But let's focus on the case for the moment.

Here is a close-up of the left side of the virginal. Descriptions of the labeled parts are below. Please ignore the horrific barrel distortion in my camera lens. The sides of the instrument really are straight in real life.




At the left end of the instrument, the end of each string is twisted into a loop, and the loop is secured around a hitch pin. This pin holds the string in place, and is buried deep in a block of wood to withstand the tension put on it when the strings are tightened. The longer bass strings attach to hitch pins along the edge of the virginal, but the shorter treble strings attach to the pins running in a diagonal line. A block of thick wood runs underneath the soundboard underneath this line; the soundboard itself is only 1/8" thick, and could never hold up under the tension of the strings. Here are three hitchpin loops, illustrating the range of wire gauges used. The rightmost wire is 8 thousandths of an inch in diameter.


Moving toward the right from the hitch pins, we come to the left bridge. The purpose of the bridge is twofold: first, it defines the speaking length of the strings; and second, it transfers vibrations from the string to the soundboard, which amplifies these vibrations into the sound you hear.

To the right of the bridge is the top jack guide, also called the register. As you can see, this guide consists of 54 slots (one for each note), each of which houses a jack. There is actually another guide inside the instrument, about two inches below the top guide, which is not visible here. Together, the upper and lower guides keep each jack in the correct plane as it travels up and down to pluck the string. Without these guides the jacks would wiggle back and forth, making it impossible to voice the instrument consistently. In historical Italian virginals and harpsichords, a single, deep guide that served the purpose of both upper and lower guides was painstakingly cut from a single piece of hardwood. If the slots were not cut perfectly, the jacks would rattle in them and make a sound one author likened to "the grunting of pigs." The finest instruments did not of course suffer from this porcine affliction, although Italian harpsichords generally suffered a bad rap for many years.

The right side of the virginal is a sort of inexact mirror image of the left side, the major difference being the presence of tuning pins rather than hitch pins.


On the left side of this photo, we see the termination of the hitch pins, left bridge, and jack guide from the last photo. The virginal is unique in that it has not one but two bridges, one at each end of the speaking length of the strings. Harpsichords normally have one bridge on the soundboard, and a nut that runs straight across the instrument, perpendicular to the strings. This nut is not fixed to the soundboard and does not transmit vibrations from the strings.


On this end, the strings are wrapped tightly around tuning pins, which are embedded in a block of hardwood called a wrest plank (underneath the soundboard). On a piano, this block is called a pin block. You use a tuning lever to twist the tuning pins, tightening or loosening the wire to tune each note.



Once the keyboard and jacks are finished, a plank of wood called the jack rail will be installed directly above the jack guide. This limits how far the jacks can travel and keeps them from flying out of the instrument and into the listeners' soup.

A decorative ornament called a rose, usually made from wood or heavy parchment, is often installed in a hole cut into the soundboard. I did not feel quite confident enough to attack my soundboard with the Black & Decker as of yet, so I decided to skip this for the time being. I may decide to add it later, although it will mean removing several strings to get at the soundboard. In any case, several authors note that the rose makes little if any difference to the sound, so it can wait. Here are some links to representative roses in the meantime:

From an Italian virginal of 1672
More information on this instrument

From a French harpsichord of 1683
More information on this instrument

The small hole in the upper right corner of the Zuckermann virginal is not a rose; a small toolbox with its cover lies in this corner, and the hole lets the player lift the cover off.