MarcoChierici

Structure

There are two kinds of piano: the grand piano and -invented later- the upright piano.

Every piano consists of four parts:

1. case
2. tailpiece
3. keyboard
4. pedals

The case is the piano equivalent of an auto's chassis. It contains all the strings and the devices that produce the sound. Grand pianos have an horizontal case, while in upright pianos the case is in vertical position.

The tailpiece consists of the strings, the metal frame that keeps them in tension, and the soundboard, made of hardwood (usually fir or beech). The function of the soundboard is to enhance the vibration of the strings by resonance.

The strings are made of steel. In the lower register, there is one string per note; going up towards the high register, every note is composed by two and eventually three strings, which are played simultaneously by one hammer.

Detail of the bass strings	Detail of the mid-high register strings
In the upper part of the pictures (taken from above), one can see a part of the dampers; under the strings, it is possible to catch a glimpse of the mechanics.

What keeps the strings in tension is a metal frame, usually made of iron. The string are attached to the frame at one end (the farthest, looking from the keyboard of a grand piano) to small spikes. The other end of the strings is attached to metal devices called pins (detail in right-hand pic). The pins are stuck in the so-called pinblock, located in the front part of the case. The tuning of a piano is performed by "moving" the pins with suitable keys, releasing or tightening the strings, and thus changing the pitch of the sound.

Keyboard

The keyboard consists of the keys and their mechanics. Keys are based on the lever principle: lowering the front part of the keys with the fingers, their rear part rises and causes a series of mechanical movements by which hammers eventually hit the strings.

In detail, when the rear part rises, the escapement pushes the hammer (which, after hitting the string, returns back); at the same time, the damper rises so that the string can vibrate.

In a normal keyboard we can count 88 keys, which cover something more that seven octaves). Some pianos, though, can have even more keys. A few years ago, the keys were 85: in fact the last three keys in the acute register (A sharp, B, C) have been recently added.

Pedals

Usually there are two pedals; in upright pianos and in some grand pianos, the pedals are three.

The rightmost pedal (also known as "THE" pedal) raises all dampers and is used to "prolong" sounds.

The left-hand pedal allow the pianist to play softer and it works in two different ways, regarding to grand and upright pianos.

In the latter ones, this pedal makes all hammers come closer to the strings, thus reducing the distance that they have to cover in order to hit the string: this results in a softer sound.

In grand pianos, the entire keyboard and its mechanisms are moved a bit to the right, so that the hammers hit just one of the three strings that compose a note. This is a better result than the upright piano technique.

As for the third pedal, again grand and upright pianos are different.

In upright pianos, it is the "soft pedal", which lowers a strip of felt in front of the hammers.

By activating this pedal in a grand piano, it is possible to keep a certain number of dampers risen: in particular, it affects only those dampers that are already risen at the time the pedal is pressed.