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Sat. Sun. please




CLICK HERE to go to our page exclusively for BASS WIRE.

The average medium sized piano has about 230 strings, each string having about 165 pounds of tension,
with the combined pull of all strings equaling approximately eighteen tons.



Minimum Order $20

      Priority Mail shipping for most items. UPS by request.

You MUST browse the Catalog area, and try to learn what you want. We no longer search our catalog for you.

Have this information ready:
     1. Description of parts
     2. Part Numbers
     3. Prices
     4. Dimensions where needed
BEFORE you call us please.

Make sure you are in the catalog area for your kind of piano--
Such as Grand Pianos,
Full Uprights, Spinets, etc.

If you are confused, call us for assistance.

If we do not answer the phone, we are probably here-- Just leave a message- we will return your call (it may not be the same day).

Piano wires are called "strings."  Now, isn't that confusing? 
Why not "wires" since they ARE wire?  
Answer:  Ask JS Bach or one of those fellows.  I call them wires :-)

Replacing piano wire is not beyond the average mechanical skills IF
you read the chapters on the subject at Repair:  Chapter Seven, Number 64.  
Also, you must follow instructions in ordering very carefully. If you have
any doubts here, please send E-Mail.

For all parts possible I give you a diagram identity number so you can go to
the  diagram and double check to see if you are ordering the right part.  It is
impossible to give a "Back" button to return to so many pages, so please
use your browser's "Back" button.

Also, I give you a link to the page which tells how to make the repair or
installation of the new part.




   Search this site or the web        powered by FreeFind
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CLICK HERE for stringing tools

Avoid handing piano wires with bare hands if possible.
Acids in perspiration greatly encourage rusting.
Also, do not let a roll of piano wire get out of control.
It can fill the room with wire at once, and it can cut
you and do serious eye damage.

Ideally, use goggles and gloves when working with piano wire. Store piano wire in the driest place possible.

When cutting a piece of wire from a spool, bend a 90 degree in the wire BEFORE you cut off what you want to use. This way, the bent wire will prevent the wire from pulling out of the brake.



This is the wire with NO copper wrapping.  This wire, at about size 12, is also used commonly to remove and install
automobile windshields.  It has many uses outside of the piano trade.  Ask any BATF agent.


Instructions for duplicating treble strings.

           You MUST mic the old wires since the size changes are very small as
           the scale progresses. Precise duplication of the diameter is essential for
           volume matching.

                      METHOD ONE: To get a perfect match, mic the old wire in thousandths
                      of an inch and, using the chart below, determine the diameter of the new wire needed in
                      thousandths of an inch. Then find the size number in the left hand column.
                      METHOD TWO: Send a sample of your broken string in the mail.
                      Be sure to tape it to a piece of cardboard in your letter.
           We no longer sell single cut wire pieces per note.

RÖSLAU WIRE From Germany

Note: When certain wire is sold in wire size 12 through 22 only, this is because these sizes are the
common sizes found on pianos. Much lighter or heavier wire is used in other applications.
We can deliver wire in large lots and quantities at reduced prices. SEND MAIL for information.
The ideal way to order is to mic your wire, and use the chart below to see which wire size you need.
You may also send us samples of the broken wire. Send a piece with no kinks and not rust if possible.

One Third Pound of RÖSLAU Wire-
           See chart below for 1/4 and 1/2 lb. smaller size wire.
           Our single rolls of RÖSLAU wire come only in the metal reels and with a brake attached,
           as seen in the graphic below. This makes for a safe method of removing wire so that you
           don't lose control. If you were to hold a spool of piano wire at arms length and just let go
           of it, you would be amazed how it instantly uncoiled and filled the room with wire. It is not
           a good idea to buy this wire bulk if you do not have canisters or brakes already.
           It can also be quite dangerous.
           Metal spool of wire with brake       
                      Size 12 through 22 only   Order by wire size                                         $ 16.25 per reel


Restringing Treble Wire Kit of RÖSLAU Wire for One Piano--
           1/3 lb. reels--  Made in Germany
           This kit of wire will restring the whole treble (plain wire)
           in most pianos. 12 reels, each in its own reel.
           The brake is available below-- Part Number SH168.
See the graphic to understand the added safety in this arrangement.
           This keeps the wire from flying wild if you slip and let go of it.
           Piano wire is very dangerous and can cut or injure eyes very quickly.
           The kit includes one 1/3 lb. reel of each of the following sizes--
                      13, 13½, 14, 14½, 15, 15½, 16, 16½, 17, 18, 19, 20
           To be sure you don't have an unusual piano, check this--
           If the highest treble wire is not less than .031 in diameter, and the
           lowest treble wire is not thicker than .045, the above set will work.
           If you have different diameters than mentioned, we can still sell you
           a special priced bundle, but we need the diameter in thousandths
           of the highest and lowest wire.
           Use a micrometer to measure thousandths of an inch..                                                            Part Number-- SH-#3          $ 156.50

Brake for the above reels- This controls the wire better as you unwind it
           and store it. One brake is enough if you transfer the brake from a
           used reel as you move to the next weight wire.
Also, by bending the
           tab of the brake upward, you can straighten the wire as you unwind
           it  from the reel.
        Part Number-- SH168      $ 2.30 each


Half Pound of RÖSLAU Wire- Roslau Brand Wire is made in Germany and is preferred
           by many piano restoration technicians.
           Tolerance for error is held to .0003 inches. This is the variation in the diameter
           of the wire as it is drawn.
           This wire comes in rolls, NOT in dispensers with a brake.
           The wire comes only polished--
Rolled and wrapped-  Size 12 through 22 only
           See the instructions just below for sizing your broken strings. 
           Order by wire size                          
                                                                                            $ 17.00

One Pound of RÖSLAU Wire-    Size 12 through 22 only  Order by wire size                         $ 21.00

Two Pounds of RÖSLAU Wire-  Size 23 through 36 only   Order by wire size                        $ 43.00
                      CAUTION: Open these rolls carefully

Five Pounds of RÖSLAU Wire-  Size 12 through 22 only  Order by wire size                          $ 79.50

Canister for holding wire rolls up to one pound
           (Without this, you could have the wire escape from your control and
           literally fill the room with wire.                                                                                SH166         $ 5.95

X Clips for holding rolls of piano wire- These clips must be put on the
           roll before removingthe wire used to hold the roll intact during
           shipping. This is done by bending the ends of the X clip around
           the roll. This allows the unwrapping of lengths of wire later without
           losing control. 
                                                                      SH168-1/2A      $ 2.00
                          SH168-1/2B      $ 2.00


Mapes International "Gold" Wire-
           This piano wire is made to the highest international standards,
           but it is made in the USA. It has a high resistance to elongation
           making tunings of new wire last longer- It also has a brighter shine
           than other brands. Where the wire can be seen, many technicians
           choose this wire.
           Size 12 through 22 only- SOLD ONLY IN 1 LB. ROLLS              Order by wire size       $ 20.00
           Five pound rolls available-- SEND MAIL



There is a tool available for gauging plain wire, BUT it is very expensive.
I suggest you order wire one of two ways.

1.  Send me a straight piece of the old wire so I can match it myself.  OR
2.  Measure the diameter of the wire with a micrometer in thousandths of an inch,
           and use the chart below to choose the right wire size number.

Here is a link explaining how to use a micrometer.

If you are ordering by mail with an order form:
Be sure to write the amount--  
1/3, 1/2, One, Two, or Five Pounds-- on the Description line of the Order Form.

If you are in a metric measure area of the world, HERE IS A CONVERSION SITE TO USE.

       Wire sizes 12 through 21 come in a reel. Sizes 22 through 36 come in an X clip,
       and you may want to buy a canister to hold the wire and dispense it more gracefully.

       Cannisters are listed up this page.

       W12       .029       440
       W12½       .030       415
       W13       .031       390
       W13½       .032       366
       W14       .033       350
       W14½       .034       328
       W15       .035       306
       W15½       .036       290
       W16       .037       274
       W16½       .038       260
       W17       .039       250
       W17½       .040       234
       W18       .041       223
       W18½       .042       212
       W19       .043       200
       W19½       .044       190
       W20       .045       182
       W20½       .046       174
       W21       .047       165
       W21½       .048       160
       W22       .049       156
       W23       .051       140
       W24       .055       121
       W25       .059       105
       W26       .063       92
       W27       .067       81
       W28  No longer available  
       W29       .075       66
       W30   No longer available     
       W31       .085      52
       W32     No longer available     
       W33     No longer available     
       W34     No longer available     
       W35      No longer available 
       W36   No longer available     

RÖSLAU Specialty and Zither Wire:
       Size 4/0 through 4 come in One Quarter pound rolls.
       Size 5 through 11 come in One Half Pound Rolls.
       The wire below is NOT in a reel when you get it. It is in an X clip,
       and you may want to buy a canister to hold the wire and dispense it moregracefully.
       Cannisters are listed up this page.

Wire Size
in inches
Common Use
Feet per
Weight of
    W4/0       .006              10,204       1/4 lb.        $ 47.50
    W3/0       .007              7,462       1/4 lb.        $ 25.50
    W 2/0       .008              5,714       1/4 lb.        $ 25.50
       W0       .009              4,545       1/4 lb.        $ 25.50
       W1       .010              3,700       1/4 lb.        $ 19.00
       W2       .011              3,033       1/4 lb.        $ 19.00
       W3       .012       Zither       2,560       1/4 lb.        $ 19.00
       W4       .013       Zither       2,170       1/4 lb.        $ 19.00
       W5       .014       Zither
       Nasal Surgery
       1,886       1/2 lb.        $ 22.50
       W6       .016       Zither
       Butter Cutting
       1,428       1/2 lb.        $ 22.50
       W7       .018       Zither
       Cheese Cutting
       1,136       1/2 lb.        $ 22.50
       W8       .020       Zither
       917       1/2 lb.        $ 22.50
       W9       .022       Zither
       757       1/2 lb.        $ 22.50
       W10       .024       Zither
       Cheese Cutting
       636       1/2 lb.        $ 22.50
       W11       .026       Zither
       Fishing Leaders
       540       1/2 lb.        $ 22.50

You will need to do the math of dividing the length per pound by the amount on a reel.

Some interesting ways our customers have used piano wire:

To suspend heavy deco items
Magicians-- To hang objects so that they look suspended in air
To survey and lay out buildings
Hat bands
A seismograph in Hawaii
Hoop dresses for dolls
To cut "green" clay before firing
Spring manufacturers
To remove broken windshields
To pull electrical and computer wire through tubes and pipe
Cheese cutters
Door gongs


This wire is used to hold the piano in the old pick up truck in case you have to haul it to the dump and throw it away.  
Find it at your friendly True Value Hardware store.  Tell them Pat Summerall sent you  :-)


CALL TOLL FREE: (800) 338-8863
If there is no answer, please leave a message- we do answer our voicemail

Go to Mail Order Form for printing:


Online help available



Quite as characteristic of the piano's individuality as the hammer action itself, is the apparatus of resonance, or, as we more usually call it, the sound-board. The piano is a stringed instrument and thus claims kinship with viols and lutes and all their descendants; but ever so much more it is a resonance instrument and a percussion instrument. In fact, the true character of the piano cannot be rightly apprehended until we have realized that the string-element is really overshadowed to a considerable extent by the sound-board. The piano is just as much dependent upon resonance as upon the prior vibration of the strings. Without the sound-board the piano would have neither power nor color to its tones. Moreover, variations in the quality of the sound-board material in its construction and in the skill of its design involve parallel variations in the tonal values of pianos, of such marked and distinct character as, almost without any special physical investigation, to convince us that we must accord to the combined tone-apparatus which we call the soundboard and strings, entirely individual peculiarities and functions.

In fact I propose in this chapter to consider the soundboard and strings together as one complete structure, which for want of a better term, we might name the “tone-emission apparatus” of the piano. In this and in what follows, I do not wish to be considered dogmatic, and certainly have no intention of composing vague and involved disquisitions on the subject-matter. Practical throughout this book is proclaimed to be; but it is impossible to talk practically about the piano's sound-board and its strings, unless we have a solid basis of fact on which to found our theories. Indeed, in this particular case, as in many others, the one sure method of going astray is to rely on rule-of-thumb or traditionary notions; as the experience of numberless persons who have tried to improve the sound-board, most clearly, if painfully, indicates. Beginning therefore with a clear discussion of the phenomena seen in the action of

the sound-board and the strings, I shall try to work out the bearing of these upon the facts of piano construction as they affect the piano tuner in his work, the pianist in his playing and the piano in its durability and value.

Definition of tone-emission apparatus functions.

The object of the tone-emission-apparatus may be described as follows: to produce the characteristic piano tone, through the vibration of the strings in response to the percussive action of the hammers thereon, and through the resonating functions of the sound-board, whereby the original string wave-forms are combined, amplified, and transformed in quality as required for the purpose indicated.

That is not a neat definition perhaps, nor is it uncommonly accurate in all its parts; but for the present it is perhaps the truest description that can be assimilated. Later on we shall improve and refine the details with better understanding.

Piano Tone.

The feature of the piano which distinguishes it generally from all other musical instruments, and specially from all other stringed instruments, is the peculiar character of its tone. This is, to an extent, of course, hard and unmalleable. It possesses neither the plasticity of the violin tone nor the bitter-sweet gayety and lightness of the guitar. It is solid, yet evanescent, hard yet capable of infinite gradation in intensity. Lacking the serenity and majesty of the organ diapason, it is pre-eminent in obedience to

touch. The pianist cannot indeed sustain his tones, nor swell or diminish them at will. Here both organ and violin surpass the piano. But the pianist can color his tone almost as widely as the violinist, and withal has a touch control over dynamics which the organ entirely lacks. Thus the tone of the piano, as brought forth by a good performer, has qualities highly attractive, which, combined with the convenience of the instrument, its capacity for complete musical expression in all possible harmonic relations, and its moderate price, have made it supreme in popularity. Let us then see just how this peculiar tone is produced.

Acoustical Definition of Piano Tone.

Speaking from the view-point which we have adopted in Chapter II, it may be said that piano tone is the effect of a wave-form induced by hammers striking upon heavy high-tension stretched strings at

pre-determined points on the surface thereof; these waves having definite forms which are modified by the resonating power of the soundboard. The first important feature is that the piano tone is produced by the strings being struck; thus distinguishing the piano from all other stringed instruments.

The string is struck.

As we have already found out1 a string stretched at high tension and struck by a piano hammer, is thrown into an extremely complex form of vibration. This vibrational form consists of the resultant of a number of simple forms, which in turn are the effect of the string's vibrating in various segments as well as in its whole length. In short, the fundamental tone of the string, together with partial tones corresponding to at least the following five divisions,2 sound together whenever the hammer makes its stroke. The exact number of concomitant partials depends, partly upon the amplitude of the vibration, which depends in turn upon the intensity of the blow, partly upon choice of the point of contact of

hammer on string, and partly upon the stiffness and weight of the string.


“Touch,” of course is an important element in the control of the exact shape of the wave-form. Tone-color or character, as we are aware,3 depends upon the wave-form, and that means upon the number and prominence of the concomitant partials. That, in turn, from the “touch” point of view, means the hammer velocity in connection with the rebound thereof. That is to say, control over the wave-form of the string, as finally emitted through the medium of the sound-board, rests, so far as concerns the performer, upon his manner of manipulating the hammer so as to vary the length of time required for it

to travel from the position of rest to the string, and back; or in other words, and more roughly, in the force and rapidity of the actual excitation of the string.

Sound-Board Vibration Demonstrated.

So much for hammer and string; but how about the soundboard? I have indicated that the part played by the board is not only important but decisive. This may be experimentally demonstrated. Suppose that a long thin rod of spruce wood is made up, sufficiently long to extend the length of one room and into another. Spruce is the wood from which piano sound-boards are made. Suppose that one end of this rod is doweled into one of the ribs of a piano soundboard so that it touches the rear surface of the

board and thence runs into the next room, all intermediate doors being stopped off so that ordinarily no sound will come from one room to the other. If the open end of the rod be now brought into contact with the sound-board of another piano, leaving the dampers of this second instrument raised, the tone of the first piano when played will be reproduced note for note but in diminished volume, from the surface of the second soundboard. The same experiment may be made by using a violin as the “receiving instrument.”

This experiment shows that the soundboard of the piano has independently the power of vibrating in all the extraordinary complex of motions that arise, not only as the resultant wave of the complex motion of one string, but as the combined resultant — the resultant of resultants — of the motions of many simultaneously excited strings. The motion of a string may be compared with the operation of several forces pulling in different directions. The resultant of these forces — that is, the direction in which the net value of all the forces when compounded, is seen to lie — can be determined mathematically. So also we know that the complex vibration of one string combines into a single complex or resultant curve.1 And so also we can see that the complex vibrations of two strings, if impressed together upon a sound-board, must combine into a further resultant; a process which can be carried on indefinitely. Thus, whilst we see on the one hand that the soundboard must be capable of complex forms of motion, we can also perceive that the mechanical realization of such forms is neither inconceivable nor even particularly difficult to apprehend.

Analogy of the Monochord.

If the suggestions I have made here have any value, they must tend to give us a reasonably clear conception of a theory which may account for the peculiar operation of the soundboard and may fix definitely its place in the economy of the piano. If, in fact, we keep steadily in mind the truth that no matter how many strings may be struck at any given moment, nor how consequently complex their motions may be, these motions always must express themselves on the sound-board as a single resultant motion, it becomes clear that such resultant motion is responsible for the tone; and nothing else.

In the circumstances, we may, without unduly stretching the comparison, suggest an analogy with the monochord. This, as we all know, is a single string stretched between a hitch pin and a tuning pin over a small sound-board, with a moveable bridge which can be shifted so as to change the vibrating length of the string whenever and however desired. Now, this string has in itself the possibility of producing all the tones which can be had by shifting the bridge. No matter how the bridge be placed and therefore no matter what segment of the string be vibrating at any time, it is the same string. The same string vibrates always, but the moving of the bridge selects the particular segment which is affected. So also

with the sound-board and strings of the piano. The sound-board is a true vibrator, whose operations are representable as resultant motions of the string vibrations. The strings are selecting vibrators, impressing their own individual vibrations upon the sound-board, either singly or in combination. When a single impression is made, the board repeats the motion exactly as transmitted to it. When a complex of impressions is made, this develops instantly into a resultant motion, compounded of all the motions; or as we might better say, being the geometrical sum of all the motions.

Sound-Board a True Vibrator.

If this be a plausible hypothesis, from the mathematical viewpoint, it is just as plausible mechanically, for while it may be hard to conceive the sound-board making a thousand different kinds of motion at once, it is not hard to conceive it making a single resultant motion; nor is there any mechanical reason why it should not. For if we consider that the soundboard is a table of spruce, forcibly arched by ribbing on its back, and then so secured to the piano as to be always in a high state of tension, and if further we keep in mind that the impressibility of the board is immensely increased through its close contact with the great battery of high-tension strings communicating with it through the bridges, we can see that we have in a well-made piano sound-board nothing less than an extremely sensitive vibrator, a whole musical instrument, ready to sing as soon as it is kindled into life by the operation of the property of resonance. The sound-board of course is a resonance instrument, and it is only necessary to understand just what this phenomenon means in Sound, to complete our apprehension of the sound-board's behavior in use.


As I said above, the sound-board is the true tone-maker, whilst the strings are the selectors or selecting vibrators. The board is the central telephone station, while the strings are respectively the various subscribers' entering and outgoing lines. The strings are the nerves, the board is the brain. A dozen analogies suggest themselves. But, in any case, we cannot stop here. We must know how the board can receive the impressions which are transformed into resultant motions. What, in fact, is this Resonance?

Resonance is the property which sonorous bodies possess of impressing their vibrations upon other sonorous bodies. In the case of the tone emission apparatus of the piano, the sound-board is placed in contact with the battery of strings stretched above it, which pass over wooden bridges glued on the surface of the board, pressing upon these latter with a heavy down bearing. The strings are brought over the bridges between pins which impart to them also a side-bearing as they cross. Thus it may be seen that the sound-board is in the most favorable condition to receive any vibrations that may originate in the strings. If it can be shown that the vibrations of a string can actually be imparted to the sound-board, and can cause that apparatus to undergo a resultant vibratory motion compounded from these vibrations, then we shall have the theory of the soundboard demonstrated.

Now, since resonance is a property possessed by all substances which may form sonorous bodies, it will be understood that we are not here discussing any uncommon quality of the piano soundboard. Seeing that the physical nearest cause of sound sensations is the performance of vibratory motion by solid bodies, it follows that resonance must take place wherever that vibration can be transmitted. If then we have a body of some material thrown into vibration, it is easy to see that all other bodies of similar material in contact with it must also vibrate. Whether their frequency is the same as that of the original body depends upon the comparative masses and other qualities of the two. All elastic substances are capable of transmitting vibrations, themselves partaking of the vibratory motion in the process; and so also if the two bodies in contact be of different material, it follows that vibratory motion may be transmitted from one to the other, so long as both be elastic enough and contact be maintained. Actual physical contact, indeed, may sometimes, under favorable conditions, be eliminated, and the atmosphere alone be competent to transmit the pulse from one body to the other, as

it does from the body to the ear. This latter potentiality is translated into fact only when each of the bodies is very favorably situated for the purpose and extremely sensitive to vibratory impulse. The resonance boxes of two adjacent tuning forks furnish an example of these latter qualities.

We see therefore that there is no mechanical or physical reason why the sound-board should not at least receive the vibrations of the strings. The question therefore becomes this; does the soundboard reproduce them after it has received them; and how?

Composition of Impulses.

We have already seen (supra) that the most satisfactory hypothesis of the sound-board's functions is that which considers it as a true tone-maker; but the mind does not always grasp easily the idea of the apparently stiff and unresponsive sound-board reproducing and amplifying the complex vibrations of the strings. Yet a simple illustration will show that this is quite possible. Suppose we secure somewhere a heavy ball, or a metal weight, like a ten pound scale weight, and suspend it from a cord so as to form a pendulum. If now the cord be gently agitated until it settles into its normal period of vibration, we can determine just what its natural frequency is. Having done this, we may allow the pendulum to come to rest again, and then begin to direct against it puffs of air from the mouth, timing these so as to correspond with the vibratory motion of the pendulum. For several seconds this will have no effect, but if the work be kept up, gradually it will be observed that the weight begins to stir. Let the work go on, being careful to blow on the weight only when its direction of motion is the same as that of the breath; that is to say to blow on it only when it is moving away from one. By degrees, if the puffs of air are timed as directed, the weight will begin to swing back and forth in its regular period and at its regular amplitude or width of motion. Thus we have an experimental demonstration of the mathematical fact that if a series of small equal forces be periodically applied to a given resistance through a given elapsed time, at the end of that time the total force applied has been equal to the sum of the small forces

delivered in one unit of time corresponding to the period of one force. To take a concrete instance, if a series of taps, each one ounce in weight, be delivered at the rate of one per second until, say, 160 of them have been made, the resistance has been operated on with a force, at the end of 160 seconds, equal to a force of ten pounds (160 ounces), operating through one second. Thus we see also that it is quite possible for even the most delicate and minute vibratory motions not only to be imparted to a stiff soundboard but also to throw that board into resultant motion. For if we consider that the middle tones of the piano are produced by frequencies running from 200 to 800 vibrations per second we can easily see that what is possible in the extreme case here described is more than possible — ^nay, is inevitable — in the case of the specially prepared, highly elastic and tensioned sound-board, especially when we remember that the strings, being struck, are set in relatively violent agitation, and communicate a relatively more powerful vibratory impression than can be had by blowing with the breath, on a far more responsive resistance than the weight, and at many times the possible blowing speed.

Considerations like these, although they do not actually demonstrate the hypothesis of soundboard behavior here adopted, do strengthen it and tend to confirm it.

To sum up, we may say that the soundboard and strings of the piano together constitute the tone emission apparatus, that the sound-board is the main vibrator or tone-maker, that the strings are the selecting vibrators, and that the vibrations of the sound-board are resultant single vibrations due to composition of the complex of vibrations proceeding from the strings, just as the latter themselves are resultants of the complex of segmental vibrations which take place in the string when it is struck. I do not claim for this hypothesis that it is above criticism, but I am certain that it meets the facts more fairly than any other I have yet seen.

In making this analysis I have wished to prepare the reader's mind for the critical examination of sound-board construction, and especially to show reasons for some of the peculiar methods that characterize that construction and have been worked out by piano makers experimenting often in the dark. The problem of practical construction is to provide a resonance table that will not merely take up in resultant vibration the impressed vibrations of the strings, but also will properly amplify these as well as reproduce their forms. In other words, it is not enough for the soundboard to reproduce the characteristics of the tone, but to amplify it; make it loud enough. We need quantity as well as quality.


Amplification of the wave forms is of course a natural consequence flowing from the large mass of the sound-board and the consequent relatively great mass of adjacent air which can be put in vibration. The tones originally impressed by the wave-forms of the strings are therefore intensified.

Coloration of Tone by the Sound-Board.

We know that inasmuch as most piano strings are struck well above the seventh node, the seventh partial is a definite member of the partial tone procession in the piano string's wave-form. The presence of this partial tone, however, is, on a thoroughly well-made piano at least, scarcely perceptible in its influence on the tone color, although when it is markedly present in any other tonal combination, its tendency to promote harshness is at once discerned. This partial and its multiples, as well as the ninth and others above it which are not eliminated in the upper regions of the piano on account of the high striking point, would have a much more distinctly hardening effect on the tone than is the case, if it were not for the fact that a properly made sound-board undoubtedly modifies these and other odd-numbered partial tones, at least as to their intensity. Thus we have another function of the soundboard which must be considered, namely the tone-qualifying function.

Proper Vibration of the Sound-Board.

It is evident from what has already been said that the piano sound-board is a sensitive vibrating instrument and therefore must possess a proper period of vibration all its own. That this is so is plain

from the facts of the case. The board is arched, or crowned, by means of ribs planed arch-wise and

glued to the back of the board, so as to draw the front surface into tension and press the rear into compression. It is then fastened into the wooden back of the piano by being glued along its outer edges, so that it remains permanently in such a way that it is continually in a "live" condition, ready to vibrate. But it is also necessary to take into account the fact that the piano soundboard is covered by an iron plate, which bears the strain of the stretched strings. If we examine the iron plate and soundboard of a piano after stringing, we shall see that the entire structure thus formed, as well as the wooden back, is in a condition partly of compression and partly of tension. Hence the whole structure has its own regular period of vibration and its own proper tone.

The object of sound-board design therefore must be to take advantage of the proper vibration of the board, plate and back together, and to see that the relative importance of each element is retained, without any one being unduly prominent. The fact is, of course, that since the soundboard is the true tone-maker, and since the iron plate and back are in such close contact with it, each of the two latter exert a constant modifying influence on the vibratory activity of the board. In short, the various materials of which the back-structure (board, plate and back) are made, all exert their individual influences, so that the ultimate vibratory period and composition of the wave-form proper to the soundboard arises out of all these forces compounded. Hence the question of the dimensions and design of each of these elements is almost equally important.

I have made this digression because it is important that the tuner should understand the reasons for differences in tone-quality as between various pianos. I shall not go into small detail regarding the design of these elements because that is the province of a technical treatise on piano construction and has been treated elsewhere.1 The following remarks are appended, however, treating generally of the influence of the parts mentioned.

Influence of the Iron Plate.

The cast iron of the plate is of course considerably stiffer and more rigid than wood. Its weight-for-bulk is also much greater ; or, in other words, its specific gravity is represented by a higher index. Now it is

well known that the vibratory form of any body which is enough under tension to induce susceptibility to vibrative influences is modified by the factors of density and rigidity. On the whole, any increase in density and rigidity tends to produce a wave form in which the higher partials are undamped. The more “yielding” structure of wood, as it were, has a damping effect on the less powerful partials, or rather, perhaps, is incapable of so elaborate a subdivision under the influence of the string vibrations. Hence the wood of the soundboard will, if left to itself, act as a damper on all the feebler partials of the strings,

however many may have been left after the rebound of the hammer. The tone quality, there fore, is founded on a partial-tone series scarcely extending above the eighth, with perhaps a trace of the multiples of the even numbered partials. Iron, however, modifies this procession by taking up the higher partial vibrations of the strings and reproducing them in amplified form. At least this is the most plausible explanation of the plate's activities, for it is certain that the more iron we have in close touch with the strings, at the extremities and on the bearings thereof as well as around the sound-board area, the harder and more “metallic” is the tone; which of course means the existence in the tonal complex of high dissonant partials. Thus it is plain that the iron plate should be so designed as not to overload the structure, and especially so as not to usurp all the functions of bearing. Wooden upper-bearing bridges are often useful in a piano which otherwise would produce a harsh and metallic tone. Excessive bracing or barring and undue massiveness are also bad features. In fact, we may say that the plate should be as light as possible ; the lighter the better so long as it is strong enough to stand the string strains. This of course greatly depends on the precise tensions at which the strings are stretched, which again depends on the dimensions of the strings. But, as we shall shortly see, scientific design tends to emancipate us from the false gods of excessive tension, hardness of wire and “bing-bing” tone.1

Influence of the back.

The technical impossibility of producing an iron plate of the ordinary thin-sheet type, strong enough to bear the entire strain of sound-board and strings, without at the same time being too enormously heavy, has necessitated the use of a very massive wooden back.2 This back, of which I have already given some description, is extremely large and clumsy, and necessarily so.3 Its effect on tone can only be de-

scribed as deadening; for there is no doubt that the natural vibrations of sound-board and plate are very much damped by the drag of the back. On the whole, therefore, we can only wish the utmost success to the inventors who have been trying during the last twenty-five years to furnish us with practical substitutes for the wooden back; although it should not be overlooked that the plate vibrations are not to be encouraged so much as those proper to the sound-board. The inventions of Wm. Bauer of Chicago point the way to a successful solution of this problem, unless I am much mistaken.

Dimensions of the sound-hoard.

The soundboard is limited, of course, according to the size of the piano, and therefore no particular rules can be given for length and breadth, or even for shape. It is to be observed however that the size of the piano and the tension and other features of the scale will require parallel modifications in the

size and thickness of the board ; that is in the vibrating area. But this is a matter which, in the nature of the case, must be determined by experiment. The point is that the board must be free to vibrate, in the particular situation created by the other conditions of the piano. If it is too heavy it will vibrate feebly on light playing, whilst with heavy playing its vibratory form will incline to be too much in its own proper period, thus smothering the resultant vibrations selected by the strings. If it is too light it will respond in light playing too readily and so again its proper vibration will intrude, whilst on heavy playing it will be unable to respond strongly enough to provide sufficient support to the strings. Thus the thickness must be graduated to the size. In practice piano makers have found it well to vary the

thickness of the board between the two extremities. Thicknesses running from 3/8" in the treble to 1/4" in the bass are usual. But these are experimental matters and can be determined only experimentally.


The sound-board must be ribbed in order to stiffen its surface and enable it to resist the various strains put on it. These strains are (1) the down bearing of the strings; (2) the tension of the strings; (3) the opposed tension and compression of upper and under surfaces due to the crowning. The crown is necessary in order to give a proper bearing and also to resist the downward pressure.

It is likewise useful in promoting the necessary tension for free vibration. The ribs are planed into curved surfaces where they are glued on to the board, so as to produce the crown, which also is further promoted by being glued on to slanted “linings,” as they are called, in the back structure. It is customary to use from 12 to 14 ribs and these should be placed so as best to sustain the strains without being too heavy or having too much of a damping effect. No other rules can or need be given in this book.1


The position and curvature of the bridges are entirely governed by the string design. No special descriptions therefore need be given here, except to remark that it has become customary to build up the bridge structure of cross banded veneers of hard wood, so as to avoid any tendency to split. The pins, which are driven into the bridge to give side-bearing to the strings, represent an archaic survival from past days, in fact from the days of the harpsichord, and there is no doubt that it would be a great deal better to use an agraffe, or drilled metal stud, such as is found on the upper bearing bars of grand pianos (and in some uprights also). False beats in strings are often generated by faults in the pinning, whereby twists in the wire are produced. The bridges must be high enough to give a good down bearing and wide enough for a good side bearing. They should never be cut to permit the treble brace on the plate to pass through, but the plate design should be modified accordingly. A cut treble bridge always means a bridge that does not transmit the string vibrations properly to the bridge, and invariably involves bad tone, and rapid break-down. The greatest enemy to the conservation of piano tone is the degeneration of the board under string pressure; a process promoted by a cut bridge. Tuners may take it as true that a cut bridge means a bad piano.

Bridges should not be brought too near the edges of the sound-board, lest the elasticity of the board

in response to the vibrations transmitted by the strings be rendered valueless for those situated at the ends of the bridges. In tight places, if the string length is to be preserved (as always it ought to be), an extension bridge may save the day, as may be observed interestingly in the small 4 foot, 8 inch Brambach grand, at the bass end of the treble bridge. Bass bridges can usually be treated best on the extension system, as bass strings are nearly always too short anyhow.

These remarks will be principally useful to the reader of this book in making clear to him the cause of piano tone-production and the reasons for differences in tone quality between pianos of apparently equal grade. I shall now briefly consider the string-scale.

Functions of the String.

In Chapter II I have discussed at length the physical properties of piano strings. It is now only necessary to remark that the object of the strings is to select the particular wave-form which the sound-board is to amplify. The wave-form must first be created by the string vibration; and therefore the dimensions, weight and method of stringing are of the utmost importance.

String Dimensions.

Elsewhere I have made a tolerably complete study of string dimensions1 and here, therefore, I may be brief. The proportion of pitch from octave to octave is as 1:2 but since strings have weight and weight increases with length, this proportion will not hold good in designing string lengths. Piano makers, attempting to compensate for the factors of weight and tension, have produced various scalings of string length ranging from the proportions 1 : 1.875 to 1 : 1.9375 for each octave. In other words, instead of doubling the string lengths at each octave, each string is made 1 7/8 or 1 15/16 as long as its

octave above. Intermediate lengths should be worked out, one by one, in proportion. Practice dictates almost universally a length of 2 inches for the highest treble strings.


It is a very clumsy and altogether uardonable sin to change the gages of wire used in a scale when putting on new strings, unless it is obvious that some fatal defect in tension proportions exists.Evenness of tension is a desideratum always aimed at, but not often attained; mainly through lack of inclination to calculate closely. But the tuner should very carefully follow the gage of wire when re-stringing, for it is usually to be taken for granted that the piano as strung represents the best gaging that could be

devised, considering its scale. The wire sizes used in piano making range from gage 12 (sometimes used in the highest treble), down to gage 26 for core wire on the heaviest bass strings on large pianos. In determining what string gages to use, piano makers should attempt to obtain an even pull for each string from end to end of the scale. On the whole, the average strain of 160 pounds per string, which is common to the mass of American pianos, is too high, and a general lowering of gage would be a good thing in all probability. The high tension piano has never fulfilled the promises so lavishly made for it

thirty-five years ago. Heavy wire means higher tension. Tensions are already too high, which simply means hard, thin, metallic tone, superficial glitter and coldness. The modern piano already has much to answer for in this respect.

Striking Point.

This is another matter not always considered with sufficient care. In a good piano the point at which its hammer touches each string is chosen scientifically, for there is no more important detail in piano design than this. I have already discussed this subject in an earlier chapter (Chapter II), but it may here be observed that the tone quality of a piano is very closely associated with the position of the hammers in relation to the strings. The tendency in modern pianos is to make the striking point excessively high.

For my part I should like to see a return to the ancient fashion of low tension strings and low striking points. Of course, as we all should realize by now, the necessary tonal reinforcement of the short upper strings must be brought about by raising the striking point. But this point also is treated elsewhere (Chapter II). Commercial pianos take all these things for granted with a refreshing but somewhat disastrous naivete however, and it is to be hoped that readers will realize that in these details and the care that is taken over them rests the difference between good and bad piano making.

Bass Strings.

The use of steel, brass or copper winding for the purpose of overweighting strings artificially, so as to make up for necessary shortening of true length requirements, is as old as piano making, and older; nor has any special improvement been made in the last half century save as to closer winding and lessening of slippage. It is still far too much the fashion for piano makers merely to send to the winders a pattern showing their string lengths, leaving the weight of the strings to chance, skill or tradition. In fact, of course, the weight of a covered bass string is just as important as the length of a treble string; for reasons which must by now be apparent to every reader of this book. It is therefore most advisable to consider the question of weight, with its intimate relation to tension whenever considering the improvement of the tone of a piano by putting on new bass strings.1

Copper vs Steel.

On the whole I think it is fairly well established that copper winding is better than steel for bass strings; for the reason that the greater specific gravity of copper makes a thinner wire available to produce a given weighting. Excessive bulk is to be avoided in bass string making. Of course, copper tarnishes and in moist climates gets covered with verdigris, perhaps more quickly than the tinned steel wire rusts; but I doubt whether the difference in favor of steel is enough to justify any preference, especially as, for

the reasons above noted, copper is tonally better. The so-called “iron” covering wire is today usually a soft steel wire.2

To sum matters up, it may be said that the following points are important in any consideration of a string scale.

1. Accurate proportioning of lengths, measured string by string.

2. Careful graduation of wire thickness to assure equality of tension from one end of the scale to another.

3. Placement on the bridges with enough space for each string to vibrate freely.

4. Avoidance of grounding bridge extremities right on the edge of the sound-board.

5. Avoidance of too much iron on bearing bridges.

6. Accurate weighting of bass strings.

In setting down these facts about the string scale, I have purposely avoided going into complete details; partly because the vibrations of a piano string and the details of stringing have already been treated in this book, and partly because I have elsewhere, in a volume still in print, also discussed them quite thoroughly.3

From the tuner's view point all other necessary information is to be found in preceding chapters. The discussion of the sound-board has been purposely more complete because accurate information regarding its functions is not so readily available. Practical details are discussed in the chapter on piano repairing (infra).

1 Supra, Chapter II.

2 See Chapter II, "Resultant Motion."

3 Cf. Chapter II.

1Supra, Chapter II

1Cf. “Theory and Practice of Pianoforte Building.”

1 See infra, String Dimensions, et seq., in the present chapter.

2CF. Supra, Chapter VI

3See the Previous chapter

1For a general discussion of these points, cf. “Theory and Practice of Pianoforte Building.”

1 Cf. “Theory and Practice of Pianoforte Building,” p. 48 et seq.

1 Consult, for complete discussion of these points, "Theory and Practice of Pianoforte Building" (p. 48 et seq.) , and to some extent Chapter II of this book.

2 But the subject is highly controversial, as the discussions of the Chicago Conference of Piano Technicians in 1916 plainly showed.

3“Theory and Practice of Pianoforte Building,”p. 28 et seq., p.48 et seq., etc.