As a child, did you ever wonder how your piano works? When you were supposed to be practicing scales were you really counting the never-ending keys. Or did you disobey your mother and poke your head under the hood and pluck at the strings like a guitar? If so, you probably have a crude understanding of how a piano works. But here is a more complete guide to how your piano works.
From the outside you can see 88 keys (52 white and 36 black), three pedals, and a large and beautifully finished frame on legs. That may seem complex enough, but if you were to lift the hood you would be amazed to see more than 10,000 parts. It requires all of these parts to make the beautiful sounds that pianos are known for.
A piano is actually a large string instrument and like all string instruments sound is made by strings vibrating at a specific frequency. When you press a key down on the outside a hammer strikes a string or a set of strings arranged to vibrate at exactly the same speed. The treble notes found towards the right hand of the key board are made by the vibrating of sets of three strings whereas the bass notes found on the left side are made by sets of two strings.
On some piano models the lowest notes have only one thick string. When these sets of strings do not vibrate at exactly the same speed, they will produce different pitches and your piano will sound out of tune. As the notes progress from treble to bass (right to left) the lengths and diameters of the strings increase.
The highest notes have very thin short strings, and the lowest notes have very thick and long strings. The strings are made of steel and are very strong. The bass strings are made thicker by wrapping copper wire around the steel core. In some cases the lowest bass strings are a 1/4 inch thick.
All of the strings are stretched over a bridge which conducts the sound to the large soundboard which lies directly under the strings. It is the soundboard that amplifies the sound of the vibrating strings.
In a grand piano, the hammers strike the strings from the underside and retract almost immediately so as not to stop the vibration. There is a corresponding hammer with every key. Each hammer is made of wood and is covered with thick and tightly compacted felt. The hammers increase in size from treble to bass. After much use, the felt on the hammers becomes too compacted which creates a harsh sound. An experienced technician should be able to loosen up the felt.
As a child you probably noticed the felt dampeners and perhaps you experimented by sticking a piece of paper between them and the strings to produce a muted sound. Like the hammers, each note has a dampener. The dampener is responsible for stopping the vibration and thus the sound. As long as a key is pressed down, the dampener is held up, but as soon as you lift your finger off the key, the dampener falls on the string and absorbs the vibration.
To avoid the effect of the dampeners, use the right foot pedal. When pressed, the right foot pedal lifts all the dampeners away from all the strings at once allowing harmonious strings to vibrate at the same time. This gives a continuous sound.
The left pedal is used to make a more quiet sound. It does this by shifting all the hammers slightly to the right. This allows the hammers to strike fewer strings in the set as well as strike the strings with the softer side of the hammer's felt. The middle pedal lifts only the bass dampeners and is not often used.
This is just a brief overview of how your piano works. This knowledge should give you a better appreciation for your piano and hopefully you will now treat this amazing instrument with the care and respect it deserves.