1. A piano is a stringed instrument.
2. Strings are pulled to high tension.
3. The back posts and the cast iron plate work in concert to support the tremendous tension of the strings.


Here  are the reasons why it is necessary to have the strongest structure possible to support string tension:

* To prevent the back of the piano from warping and twisting.
* To enable the piano to stay reliably in tune between tunings.
* Without solidity in the structure the many parts of the piano could not function properly.


1. Look at the back of the piano first, the back posts are easy to see on most instruments. Notice the following things about the back posts:

* Size of the post; not only width, but depth.
* Double, triple, posts - wood grain appearance
* Post extend to the top of the piano.
* Posts extends to the bottom of the piano.


1. A piano is a stringed instrument.
2. Strings are pulled to high tension.
3. The back posts and the cast iron plate work in concert to support the tremendous tension of the strings.

These are the reasons why it is necessary to have the strongest structure possible to support string tension:

* To prevent the back of the piano from warping and twisting.
* To enable the piano to stay reliably in tune between tunings.
* Without solidity in the structure the many parts of the piano could not function properly.



* Because its the strongest wood for it's weight.
* Resists splitting and cracking.
* Spruce's lengthwise grains are straight, close and dense which provides rigid support.
* Posts are bolted to cast iron plate.


1. A piano is a stringed instrument.
2. Strings are pulled to high tension.
3. The back posts and the cast iron plate work in concert to support the tremendous tension of the strings.

These are the reasons why it is necessary to have the strongest structure possible to support string tension:

* To prevent the back of the piano from warping and twisting.
* To enable the piano to stay reliably in tune between tunings.
* Without solidity in the structure the many parts of the piano could not function properly.


As mentioned, some pianos will have metal back posts, others, will have virtually no wood back posts at all. Many high quality pianos have scale designs which provide plates that have rigid I - Beam like construction that extend to all four corners of the frame, which actually adds the strength of two or more back posts. This is an expensive process known as a full perimeter plate. This is also an acceptable method. Astin Weight -  Ibach - Knight - Some Kawais - Some Yamahas - Some Webers - to mention a few.


1. The purpose of the pin block is to firmly hold the tuning pins in place where the strings are attached.

* Tuning pins vary in quality.
* Better grades of tuning pins have machine cut threads.
* Tuning pins should be "blued steel", an electronic method to prevent rust.
* Nickel-plated steel tuning pin.

2. The pin block in many of the finest pianos in the world consists of several plies of hard rock maple. Alternate plies have grain running at ninety degrees to that of adjoining plies to assure even gripping of the pins, and to prevent splitting of the pin block.

* Material of pin block should be hard rock maple.
* Wood should be quarter sawn for strength.
* Pin block should be at least 2" thick.
* Number of plies not as important as type and cut of wood.


This is another area where you can visibly see quality. Are the hammers nicely spaced. Are they all in line. Good pianos in a console size use about a ten to twelve pound hammer. Piano hammers are made of fine wool felt which is formed around a hard-maple hammer molding. First-grade piano hammers are made of two layers of felt; the outer layer is white, the inner usually purple, green or magenta.

The layers of felt are applied separately. The forming and gluing of the felt to the hammer is done with tremendous pressure applied by hammer presses. Many tons of pressure are applied from several angles, forming the shape of the hammers.

The result is one long piano hammer which is then cut into individual heads. Holes are bored at the proper angles on the underside of each head, into which the hammer shanks are later glued. Each set of hammers is then individually and painstakingly fitted to the piano. Some hammers are stapled, others have a cotter key-like wire through the hammer to insure stability in the hammer. Many imported pianos have hammer weights of up top twenty pounds on grand pianos.

One of the least understood and most controversial subjects in the world of pianos is hammer weight. The prospective buyer is told that one piano has twelve-pound hammers, while another has only nine or ten-pound hammers. A glance into the piano tells us that surely those hammers, even all eighty-eight of them, do not weigh from nine to twelve pounds. The figure refers to the size of the felt sheets used in the making of the hammers. The felt in an individual hammer averages 109/l000ths of an ounce, depending on the weight of the sheet of felt from which it was made; and the difference between nine and twelve-pound hammers average 36/l000ths of an ounce per hammer. The important thing to remember about hammers like all other parts of the piano, is that not only the quality of the materials, but how those materials are utilized in the building of the instrument determine the overall quality of the product. In the case of hammers, the proper shape and hardness are the key factors affecting proper tone regulation. That's why it is often said that while a good hammer can't make a poor piano sound good, a bad hammer can spoil the best piano.


1. The soundboard consists of a sheet of wood;

* One thickness spruce (the term "solid" when referring to spruce soundboards is very often misleading today because some builders of pianos with laminated boards where all three layers are spruce, refer to soundboards as "solid" spruce meaning they are all spruce).
* Special taper. Starting from 6 to 9mm at the at edges (3/8 of an inch thick and beveled) as a resonator.

2. The soundboard is not flat as it appears. but has a crown held in place by a series of ribs. If the soundboard were flat or if it were to lose this crown, there would be very little volume or tone.

* The ribs are made of a lightweight wood such as sugar pine, are double notched and fitted into soundboard lining. * They are tapered to fit and correspond with the taper of the soundboard.


The next step, and one of the most critical in the making of a fine piano, is the shaping of the treble and bass bridges. The bridges, of Northern hard maple, must be planed to exact thickness from end to end, so as to provide the proper down-bearing of the strings upon the bridges. It is this correct down-bearing which is so vital to the transfer of the string vibrations to the soundboard (resulting in pleasant piano tones).

Bridges should be glued to the sounding board with hot hide glue and further secured with wood screws from the back. Such screws should have maple buttons under their heads. The bridges must be accurately notched, at both top and bottom in the case of treble bridges, for each individual note. This provides for the "stopping" of the string at a precise point in much the same way as a violinist "stops" his strings be fingering. Bass bridges are planed on both edges for the same reason.

Bridges, made from maple, must be planed to exact thickness from end to end, so as to provide the proper down bearing of the strings upon the bridges, this is measured by the use of a "bearing gauge" (See Glossary of Piano Terms).

* Bridges are glued and further secured to the soundboard.
* To prevent vibrations bridges are secured with wood screws that have maple buttons under their heads.
* Bridges are double notched.
* Bass bridge cantilevered.

A time and money-saving way to do this important bridge notching is to notch the treble bridge on the top edge only. Half the work, half the cost and many piano buyers can't tell the difference unless they are able to distinguish subtle differences in piano tone.


Every musical effect in a piano must originate in the strings. The soundboard, no matter how perfect, can only amplify the sound produced by the strings. Pianos have from 215 to 230 steel strings graduated in length and thickness to produce the 88 notes of a piano's scale design. The shortest string is about 2", the longest string may be 84" or longer.

The bass strings should be pure copper wound, not plated.

* Examine the spacing of the strings in relation to other strings, spaced evenly without touching another string.

* Depressing a key slowly, check damper alignment. At the same time, check as hammer strikes the strings.

Check to see if hammers strike all of the strings of all notes.

Inspect the strings for even spacing (not touching another string) and proper alignment with the dampers.

Listen to the piano - Is the tonal output powerful enough, at least impressive enough that you should expect from a "classic" piano, but capable, nevertheless, of filling a room no larger than 15 square feet or of a volume not more than say, 2500 cubic feet ?

Is the tonal output reasonably mellow (very bright indicates hardened hammers from age or dry climatic conditions).

Is the tone even and with a fair singing quality ?

Is the action satisfactory, that is, does it give a fairly elastic response to your touch ?




Briefly stated, the way a piano action works is that the down pressure on a key is converted to a forward motion of the hammer towards the strings. The hammer travels five times as far and approximately four times as fast as the front end of the key does, the key travel being only about 3/8 of an inch at its front edge. This is accomplished through a remarkable system of levers and pivots which, for a quality piano, must be adjusted to the utmost accuracy, making the action so responsive to the player's touch on the keys that there is almost no limit to the musical effects obtainable. For a better, more natural leverage, piano keys slope slightly downward towards the back and become level when the key is depressed.

A piano action would be a fairly simple mechanism if, when you depressed a key, it just had to push the hammer against the string. But if it worked that way, there would not be much tone because the hammer would stay against the string and, acting as a muffler, would stop it from vibrating. Thus, it would not have had time to return to its starting position after you released it.

Consider the manufacturing problem created by the fact that thousands of the parts in a piano are moving parts, that many are very small and that on some of them a variation of a thousandth of an inch will affect their performance. Not only is the utmost precision required in making and assembling the parts, but they must operate quietly and resist friction, wear and loss of accuracy under long and strenuous use. The materials used today for the best piano actions are largely wood, felt, woolen bushing cloth and leather. Like all products of nature, these items are inclined to be unstable when exposed to varying climatic conditions, although this hazard is greatly reduced in the better pianos by use of the highest quality materials and by superior workmanship.

If metal could be used, it would simplify the manufacturing problems and substantially reduce the cost; however, metal (not being noiseless without frequent lubrication and adjustment) does not lend itself to the purpose and very little of it is employed. Many other materials, including all kinds of synthetics, have been tried, but, with few exceptions, have not proved success, imagine a hinge or bearing that would work smoothly and silently for fifty years or more without lubrication or constant adjustment. Every pivot in a piano action must do this and they do it because these moving parts are held in a circle of specially made material called bushing cloth. Action hinges or pivots are made by boring holes in wooden parts, lining the holes with this bushing cloth, then connecting the adjoining parts with German Silver center pins which will rotate in these cloth bearings indefinitely without attention unless exposed to the most abnormal climatic conditions. This cloth, among its many other properties, must be uniform in thickness to an unbelievable degree. The makers allow a tolerance of 2 one-thousandths of an inch, plus or minus, which is less than one-half the thickness of an ordinary business card and is an incredible measurement for such material. It requires a total of ninety-six different operations in the felt mill to produce the superior grades of this cloth used in actions.

To summarize the story about piano actions, good performance is not only a question of superior materials. but also involves skill, experience and the willingness of the piano manufacturer to spend the extra money to have these important hidden parts as accurate and dependable as it is possible to make them.


Most piano manufacturers offer three pedals. On most vertical pianos the pedal to the right is a full sustain pedal and by depressing it, the piano tone will linger on or sustain the note. The left pedal is known as the "Una Corda", which softens or limits the power of the tone by moving the action forward and limiting the distance the hammers travel. On a grand piano it shifts the action slightly, enabling the hammer to strike fewer strings.

A third pedal in the middle varies from brand to brand. It may serve to sustain the bass notes only, or it may act as another form of soft. In some cases, it drops a piece of felt to provide a muffler, or practice pedal.

On a grand, it becomes a true "Sustenuto", that is, allowing the pianist to sustain many notes as long as the pedal is held. A good way to tell about the quality of a piano is to hold a pedal in your hand and get a feel for it. Twist it and push it, then go to a more expensive piano and compare. You'll see the difference in quality.

As a final point of clarification, many very fine pianos in the world only have two pedals, and for many years many American pianos including Steinway only used two pedals on many verticals. The center pedal on vertical pianos is an extra feature which can be a mute, a form of soft, or even a bass sustain. There is nothing wrong with having two pedals on a piano. For many years, that is all anyone had.


Like the speaker of a radio, a piano's sounding board is a vibrating diaphragm. To work properly, the board must always be under tension. This is accomplished by having the center of the board arched, or crowned, with the strings pressing down on the board where they cross the bridges. The vibrations of the strings are thus transmitted through the bridges to the sounding board, where they are greatly amplified by the board and projected into the air to reach our ears.

The piano string acts as a tone generator. The sounding board's function is to truly reflect and amplify that tone. The sounding board is the most important single part in the piano because if the board is bad, you do not have a piano until there has been a major repair job. No real music can come out of a conventional piano except through the sounding board. So that it will vibrate freely, a sounding board is necessarily a very thin panel, usually from 3/16 to 3/8 of an inch thick. Ribs are added to stiffen the board and to help preserve the crown. The reason the ribs are shaped at the ends is to allow the board more flexibility around its perimeter. Until recent years, all piano sounding boards were made of solid lumber pieces glued edge to edge. Wood, however, has an irresistible tendency to absorb or lose moisture according to the humidity content of the surrounding air. Absorption of moisture causes the conventional sounding boards to expand, increasing the tension of the strings and, thus, raising the pitch. Conversely, the pitch is lowered when the board dries out. It has been a constant struggle to try to keep such sounding boards from splitting or from losing their all-important crown. To obtain perfect musical results, there must be good contact between each of the strings and the board. This perfect contact cannot be maintained if the board loses all, or even part, of its convex form (crown). Piano sounding boards are made of wood because no other known material amplifies musical tones so well.


The case is made of veneers of oak, walnut, or other outer finish. It has a core made up of cross sections of another yet cheaper form of wood, pressed wood, or chipped wood, which are totally acceptable in and by today's standard because they are for cosmetic appearance only and should not wear out..

Next, is the beauty of case design and finish. The standard cases are made or finished in mahogany, walnut, ebony, rosewood, oak, fruitwood, pecan or pine. The two first named are the more popular. All are dependable if the piano is well made. The manufacturing process for pianos does not readily lend itself to automation, due to variations in the acoustical qualities in pieces of wood. These variations require skill in selecting the wood stock and conditioning it to specific moisture levels. Many of the other labor - intensive functions such as voicing, tuning and regulation require skills based on years of experience. For these reasons the piano is still handcrafted in many respects.