The Grand Piano

Instruments can be divided into three categories based on how they produce sounds. Those categories are string instruments, wind instruments, and percussion instruments. The piano's ancestry can be traced back through various instruments such as the clavichord, harpsichord, and dulcimer. But if it were traced back even further, one would find that the piano is a descendant of the monochord. In other words, based on its ancestry the piano can be classified as a string instrument.

Origin:The Piano Has the Same Mechanism as the Dulcimer

Although the piano can be classified as a string instrument due to the fact that the sounds come from the vibration of strings, it can also be classified as a percussion instrument because a hammer strikes those strings. In this way it is similar to a dulcimer. The dulcimer is an instrument that originated in the Middle East and spread to Europe in the 11th century. It features a simple resonating box with strings stretched on top of it. Much like a piano, a small hammer is used to hit the strings, which is why the dulcimer is considered to be a direct ancestor of the piano.
The piano is also considered to be a part of the keyboard family. The history of instruments with keyboards dates far back and originates from the organ, which sends bursts of air through pipes to make sound. Craftsmen improved upon the organ to develop an instrument that was a step closer to the piano, the clavichord. The clavichord first appeared in the 14th century and became popular during the Renaissance Era. Pressing a key would send a brass rod, called a tangent, to strike the string and cause vibrations that emit sound over a range of four to five octaves.
Created in Italy in around 1500, the harpsichord later spread to France, Germany, Flanders, and Great Britain. When a key is pressed, a plectrum attached to a long strip of wood called a jack plucks the string to make music. This system of strings and soundboard, and the overall structure of the instrument resemble those that can be found in a piano.
The piano was invented by Bartolomeo Cristofori (1655-1731) of Italy. Cristofori was unsatisfied by the lack of control that musicians had over the volume level of the harpsichord. He is credited for switching out the plucking mechanism with a hammer to create the modern piano in around the year 1700. The instrument was actually first named "clavicembalo col piano e forte" (literally, a harpsichord that can play soft and loud noises). This was shortened to the now common name, "piano."

Great Composers Who Followed the Advances of the Piano

Gottfried Silbermann, a specialist in constructing organs, took over the work that Cristofori began. He studied Cristofori's designs and improved upon them. Not long after in 1747, Johann Sebastian Bach performed one of his historical pieces in front of Frederick the Great on the piano that Silbermann dedicated to the king.
A man that contributed greatly to German piano manufacturing was Johann Andreas Stein (1728-1792). Stein improved upon the Silbermann piano mechanism and developed what would later be called the Viennese action, a new system that was used for many years and gained much popularity. This new piano featured a bright tone quality and a keyboard that responded well to the player's touch. Mozart fell in love with these aspects of the new instrument, on which he wrote many renowned piano pieces.

Meanwhile, Johannes Cristoph Zumpe in England introduced a hammer action to the clavichord and produced a square piano. One of the first known uses of a piano as a solo instrument in public concert was a performance in 1768 by Johann Christian Bach (son of J.S. Bach), and this square piano was the one used on that occasion. Later, John Broadwood in England added improvements to the English action that Zumpe invented, increasing the elasticity of the strings, and also strengthening the frame. His English action (in around 1780) produced a touch with a lower sense of resistance and a more powerful sound. In that regard, this instrument can be termed the precursor to the modern piano. In his later years, Beethoven wrote many masterpieces on this piano made by Broadwood.
When a key is pressed, a hammer inside the piano strikes the strings from below. However, this only produces a soft sound. One end of the strings is supported on bridges, which are attached to the soundboard. The vibrations of the strings are transmitted to the soundboard through the bridges, and a loud sound resonates as a result of the soundboard vibrating the air. The entire piano, notably the soundboard, vibrates to produce sound.
The mechanism of the piano that causes hammers to strike the strings when a key is pressed is called the "action." When one speaks of the history of the piano action, mentioning the repetition mechanism (double escapement) invented by Sébastien Érard of France is a must. This mechanism allows the pianist to quickly repeat a note without having to fully release the key. Up until the introduction of this mechanism, when a key was depressed, the hammer usually rose and struck the string and was not ready for the next keystroke, until it had fallen back to its at-rest position. Erard's invention made it possible to prepare for the next keystroke even though the hammer had not completely fallen back to its at-rest position.
t is said that Erard presented a prototype of this mechanism to Beethoven in 1803, and this helped the great composer write new works. This mechanism has also been passed down in a more refined form in today's modern actions. Look carefully at the movement of the levers. The hammer rises up partway through its movement. This allows it to respond correctly and produce sound, even when played many times in succession. Functionally, the key can be played a maximum of 15 times per second.
The damper mechanism is another important part of the action. This mechanism quiets the sound instantly as soon as the finger is lifted from the key. In the photograph, the four white parts are the damper felts. When the finger is lifted from the key, the dampers touch the strings from above and stop the strings from vibrating. A damper weight is attached to the bottom of the long vertical wire.
A piano keyboard has 88 keys. The number of strings depends on the model, but is usually around 230. For the tenor and treble notes, three strings are strung for each key, and for bass notes, the number of strings per note decreases from three, to two, and then to one as you approach the lowest bass notes. In addition, the strings become shorter in length going from low-pitched notes to high. The thickness of the string changes in steps, and the higher the pitch of the note, the thinner the string. Strings for bass notes are wound with copper wire, while strings for tenor and treble notes use bare wire and are not wound.
The three strings for middle pitch and high pitch notes are not only intended to increase the volume during play, but also enrich the quality of the sound. Even though the three strings that correspond to the same note are hit by one hammer, the point at which the hammer makes contact and the positions of supports vary between the strings, so the three strings do not oscillate in exactly the same way, bringing life to the reverberation of the strings after they have been hit and a rich, full quality to the sound.

Let's compare the sound when variation in the vibrations of the strings have been deliberately introduced. With one of the strings tuned to A at 440 hertz, example one has the other two strings tuned 1.5 cents higher and lower, example two has them each at an interval of 1.0 cents, and the third example has them each differing by 0.5 cents. Example four has the three strings tuned to the same 440 hertz frequency. One cent is equal to the difference in frequency for one hundredth of a semitone interval on the equal temperament scale. The examples above use an artificial piano sound with exaggerated pitch interval, in order to make it easier to identify the difference in the reverberation of the strings after they have been struck. Quantifiable differences in the piano sound can be identified depending on how the vibrations of the three strings vary. Professional piano tuners are able to discern even more subtle distinctions in tone by ear, in order to tune the instrument to produce the richest quality of sound.

The way individual strings are designed also enriches the tone. A bridge supports one end of the string. For strings of bass and middle range the other end is supported by an agraffe, and for treble notes, by a part called a bearing. The segment of the string between these supports is called the "speaking length." For the A note in the exact center of the compass, the string will vibrate at a frequency of 440 hertz, i.e., 440 times per second. In the treble section of the compass, resonating segments at the front and back of the string are called the front duplex and back duplex respectively. These segments vibrate sympathetically with the speaking length, and increase the attractiveness of the sound. With no resonating segments at all, the tone is less rich.