The Sound Post

The Luthier's Apprentice

Chapter 22: The Sound Post

The sound post is a dowel of spruce six millimeters in diameter and approximately fifty-two millimeters long, a cylinder so small that it can be held between the thumb and the forefinger, so light that it can be balanced on the tip of the index finger, so plain that it looks like nothing, looks like a scrap, looks like the offcut from a larger operation, the kind of piece that a person who did not know what it was would sweep from the bench into the bin without a second thought, and the not-knowing would be the error, because the sound post is the most acoustically significant single element of the violin, more significant than the arching, more significant than the graduation, more significant than the f-holes or the bass bar or the varnish, the sound post the element that determines the balance between the treble and the bass, the element that couples the top plate to the back plate, the element that transforms two separate vibrating surfaces into a single unified acoustic system, and the transformation is achieved by a dowel of spruce the size of a pencil, and the dowel is not glued.

Not glued. Not fastened. Not secured by any adhesive or mechanical device. The sound post is held in position by friction alone, by the pressure of the two plates against its ends, the top plate pressing down and the back plate pressing up and the sound post wedged between them, the wedging the fit, the fit the function, the function the sound. The sound post can be moved. The sound post can be adjusted. The sound post can be repositioned by inserting a thin metal tool through the f-hole and pushing the dowel a fraction of a millimeter in any direction, and the fraction of a millimeter changes the sound, changes the balance, changes the character of the instrument, the instrument's voice altered by a movement so small that the eye cannot see it, the movement visible only in the sound, the sound the evidence, the sound the measure.

Giovanni taught Nadia to set the sound post on a May afternoon. The teaching was the last of the technical lessons, the last of the skills that the apprenticeship would transmit, the sound post being the final element of the violin's construction, the element that was installed after everything else was complete, after the body was closed and the neck was glued and the fingerboard was fitted and the pegs were installed and the varnish was cured, the sound post the last act, the act that completed the instrument, the act that gave the instrument its voice.

He held the sound post between his thumb and forefinger. He held it up to the light from the north-facing windows and the light illuminated the dowel, the grain of the spruce visible in the small cylinder, the grain running the length of the dowel, the grain tight, the grain the same tight grain of the Val di Fiemme spruce that constituted the top plate, the grain the identity, the identity the material, the material the sound.

He said: the Italians call it l'anima. The soul. Then he rolled the small dowel between his fingers and corrected the romance of the word with the plainness of the object. Spruce, cut clean. Ends matched to the plates. Too short and it falls. Too long and it bruises the instrument from the inside.

L'anima. Nadia heard the word and added it to the Italian she had been learning for eight months, the Italian of tools and wood and pressure, the Italian that lived on the bench more than in the mouth. The word mattered. The fit mattered more.

Giovanni showed her the sound post setter. The setter was a thin metal tool, a rod approximately twenty-five centimeters long with a forked tip at one end and a bent tip at the other, the forked tip for gripping the sound post and the bent tip for adjusting it once it was inside the instrument. The tool looked too small for the importance of the task. That was one of the workshop's jokes: the most decisive work often arrived on the least impressive tool.

He demonstrated on a practice violin. Not the last violin, not the instrument that was being built, but an older instrument, one of the violins from the front room wall, the instrument taken from its peg and placed on the workbench, the instrument serving as the teaching instrument, the instrument on which Nadia would learn before she was permitted to approach the instrument that mattered, the learning on the practice instrument the same principle as the learning on the practice plate, the principle that the ruining must happen on the thing that can be ruined, the thing that can absorb the mistake without loss.

He removed the strings. He loosened the pegs and removed the strings and removed the bridge, the bridge lifted from the top plate and set aside, the top plate now bare, the f-holes open, the interior of the violin visible through the f-holes, the interior dark, the interior the space in which the sound post would be set, the space between the top plate and the back plate, the space that was the violin's acoustic chamber, the chamber in which the sound was born.

He showed her the current sound post. She looked through the right f-hole and she could see it, the small dowel standing between the plates, the dowel pale in the darkness of the interior, the dowel standing like a column in a temple, the column supporting nothing visible but supporting everything audible, the column the connection between the top and the bottom, the connection that was the coupling, the coupling that was the sound.

He inserted the setter through the f-hole. The forked tip gripped the top of the sound post. He twisted the setter and the sound post tilted, the friction between the dowel's ends and the plates releasing, the release allowing the sound post to be moved, and he moved it, tilted it, pulled it toward the f-hole, and the sound post came through the opening, the dowel emerging from the violin's interior like a splinter extracted from skin, the emergence the removal, the removal the beginning of the lesson.

He held the removed sound post. He held it next to a new sound post, a new dowel of spruce that he had prepared, the two dowels the same diameter but slightly different in length, the new dowel cut to the specific length that this instrument required, the length measured by Giovanni using a caliper inserted through the f-hole, the caliper measuring the distance between the inner surfaces of the top plate and the back plate at the position where the sound post would stand, and the distance was the length, and the length was cut, and the cutting was precise, the dowel cut with a knife, the ends cut at a slight angle to match the curvatures of the inner surfaces, the angle the fit, the fit the function.

He said: the length must be exact. Too short and the post falls. Too long and the post distorts the plates, pushes the top plate up and the back plate down, the distortion visible as a bump on the top plate's surface, the bump the sign of a sound post that is too long, the too-long the error, the error audible in the sound, the sound becoming harsh, the harshness the distortion, the distortion the too-long. The exact length is the length that holds the post in position by friction without distorting the plates, the length that creates the pressure without the force, and the pressure without the force is the correct fit, and the correct fit is the setting.

He inserted the new sound post. He gripped it with the setter's forked tip. He angled the setter through the right f-hole, the angle precise, the angle allowing the dowel to pass through the narrow opening without touching the edges, the touching the risk, the risk of chipping the varnish at the f-hole's edge, the chip the damage, the damage the error, the error the care, the care the craft. The dowel passed through the f-hole and entered the dark interior and Giovanni manipulated the setter, the setter turning, the dowel tilting, the dowel finding its vertical orientation, the dowel standing between the plates.

He positioned the post. The position was behind the right foot of the bridge, close enough to measure and fine enough to distrust the measurement. He moved the post with the setter's bent tip, a fraction of a millimeter at a time. Set. Tap. Listen. Move again.

He tapped the top plate. He tapped with his knuckle, the knuckle striking the surface above the sound post's position, and the plate rang, and the ringing was a pitch, and the pitch was a frequency, and the frequency was the information, the information telling the maker about the coupling, the coupling between the top plate and the back plate, the coupling that the sound post mediated, the sound post the mediator, the mediator the soul.

He adjusted. He moved the post a hair's breadth to the south. He tapped again. The pitch changed. The change was subtle, nearly hidden inside the wood, but Giovanni heard it. Nadia was beginning to hear it too: tightness when the post pinched, hollowness when it stood too far from where the bridge wanted it.

He moved the post again. He tapped. He listened. He moved. He tapped. He listened. The cycle repeated until the sound lost its complaint.

He stopped. He tapped one final time. He listened. He nodded.

The nod was the conclusion. The post was standing with the pressure he wanted, at the angle he wanted, in the place where the treble did not bite and the bass did not thicken.

He handed the setter to Nadia.

The handing was the teaching. Now she had to do it with her own hand.

She took the setter. She held it in her right hand. The tool was light, was thin, was unremarkable in its appearance, a rod of metal with two tips, but the unremarkable appearance was the disguise, the disguise concealing the importance, the importance the thing that could not be seen but that could be heard, and the hearing was the purpose, and the purpose was the setting.

Giovanni removed the sound post he had just set. He removed it with the spare setter, the dowel extracted through the f-hole, the dowel handed to Nadia, the dowel in her left hand, the setter in her right hand, the two objects the tools, the tools the lesson.

She gripped the dowel with the setter's forked tip. She angled the setter toward the f-hole. She inserted the dowel through the opening. The dowel passed through the f-hole and entered the dark interior and Nadia felt the dowel's tip contact the inner surface of the back plate, the contact the arrival, the dowel inside the instrument, the dowel between the plates, the dowel waiting to be positioned.

She manipulated the setter. She turned it, trying to stand the dowel upright, trying to find the vertical, the vertical the orientation, the orientation the first step. The dowel tilted. The dowel leaned. The dowel fell, the dowel tipping over inside the instrument and lying on the inner surface of the back plate, the lying the failure, the first failure, the failure of the first attempt, and the failure was expected, was normal, was the practice plate of the sound post setting, the failure the beginning of the learning.

She tried again. She gripped the fallen dowel through the f-hole, the setter's forked tip finding the dowel in the dark interior, the finding the skill, the skill of working blind, the skill of the hands working in a space the eyes could not see, the skill that required the hands to develop their own sight, the sight of touch, the sight that felt the dowel's position and the dowel's angle and the dowel's relationship to the plates, the relationship that the hands assessed without the eyes, the assessment the touch, the touch the craft.

She stood the dowel. The dowel tilted and she corrected, the correction the adjustment, the adjustment small, the setter turning a degree, two degrees, and the dowel straightened, the dowel approaching the vertical, the vertical the goal, and the goal was approaching, and the approaching was the skill, and the skill was building.

The dowel stood. It was vertical, wedged between the plates, held by friction. It stood in approximately the correct position, approximately behind the right foot of the bridge, approximately the correct distance from the center line. The approximately was visible in the way Giovanni did not yet move his head.

Giovanni tapped the plate. He tapped above the sound post and the plate rang and the ringing was a pitch and the pitch was not the pitch that Giovanni's setting had produced, the pitch slightly different, the difference the position, the position slightly off, and the slightly-off was the learning, the learning in the difference between the master's pitch and the apprentice's pitch, the difference the distance, the distance the thing that the practice would close.

He looked at Nadia. He looked with the assessing attention. He did not correct her. He did not take the setter from her hands. He did not adjust the post himself. He looked and the looking was the instruction, the instruction to listen, to hear the pitch, to hear the difference, to hear the distance, and the hearing was the lesson, and the lesson was: move it.

She moved the post. She inserted the setter's bent tip through the f-hole and she pushed the post, the push gentle, the push a fraction of a millimeter, the fraction the variable, and the post moved, and she withdrew the setter, and Giovanni tapped, and the pitch changed, and the change was in the correct direction, the pitch moving toward the pitch that Giovanni's setting had produced, the pitch approaching, the approaching the learning.

She adjusted again. Push. Tap. Listen. Push. Tap. Listen. The cycle that Giovanni had performed became smaller in her hand. If the sound tightened, she eased the post back. If it hollowed, she moved it forward. If the pitch blurred, she changed the angle and tried again.

She stopped. She tapped the plate herself. She listened. The pitch was close. The pitch was not Giovanni's pitch, was not the master's pitch, was the apprentice's pitch, the pitch that was close enough to be recognizable and far enough to be improvable, and the improvable was the future, the future being the next attempt and the attempt after that and the fifty years of attempts that would follow if she continued, if she stayed, if she committed to the craft.

Giovanni tapped. He listened. He did not nod. The not-nodding was the assessment, the assessment that the position was close but not correct, not yet correct, the not-yet the apprenticeship, the apprenticeship the distance between the close and the correct, the distance that the practice would close, the practice that was the years, the years that were the craft.

He said: again.

She removed the post. She reinserted it. She positioned it. She adjusted it. She tapped. She listened. She adjusted again.

The afternoon passed. The light from the north-facing windows moved across the workshop in the slow progression of the May afternoon, the light the clock, the clock the work, the work the setting of the sound post, the setting repeated, the repetition the practice, the practice the learning, the learning the craft.

She set the post ten times. Each time the position was slightly different. Each time the pitch was slightly different. Each time she had to remember where the tool had been, how much pressure she had used, what the tap had given back. The learning did not feel like ascent. It felt like trying to move a standing matchstick in the dark without knocking it down.

On the tenth attempt Giovanni tapped and the pitch was close, very close, within the range that he accepted, and he looked at her and did not nod. His eyes changed instead. Not praise. Acknowledgment that the skill was entering the hands.

She held the setter in her hand. She held it the way she held all the tools now, with the familiarity that eight months of daily practice had developed, the familiarity that was not mastery but competence, the competence that was the foundation, the foundation on which the mastery would be built, the building the years, the years the craft.

The sound post stood inside the practice violin. The dowel of spruce, six millimeters in diameter, wedged between the plates, held by friction, not glued, not fastened, the soul of the instrument held in place by nothing more than the pressure of the wood against the wood, the top plate pressing down and the back plate pressing up and the dowel between them, the dowel the connection, the connection the coupling, the coupling the sound.

Move it a millimeter and the voice changes.

This was the lesson of the sound post. The smallest hidden thing could change the whole voice, and it did so without glue, without a nail, without any visible authority. Spruce under pressure. Wood answering wood.

Giovanni took the setter from her at the end of the afternoon and placed it on the bench.

He said: tomorrow, again.

The sound post stood inside the practice violin, invisible unless she bent to the f-hole and looked for it.

She could hear it anyway.