Basic Piano Parts

Piano Action

The Vertical Piano Action is made of approximately 3,600 piano parts and is synonymous with piano keys for many of us. This is particularly true of someone who has only watched dexterous hand movements of pianists creating the magic of music and who has never played a piano.

But the piano parts of an upright action represented by the keys is the tip of the ice berg. At the back of the keys inside every piano is a system of levers that transfer the slightest touch of the fingers on the keys through to the strings and subsequently to the soundboard and our ears.

Each piano key sits on a "balance rail" which allows the key to act as a lever, much like a teeter-totter. When the front of the key is pressed down, the back goes up. On the back of each key a whippen rests (itself made of many piano parts)which moves upward as the key is depressed at the front of the piano.

One of the piano parts of the whippen, a part which looks like a "J", called the Jack, sits underneath the bottom of the hammer assembly. As the whippen is pushed upwards by the whippen, the jack in turns pushes the hammer up. However, since the bottom part of the hammer assembly is attached to the hammer rail (part of the action frame) instead of going straight up, it swivels and the hammer follows an arch propelling it towards the strings.

Just before the hammer reaches the string the jack must be gotten out of the way, or else the hammer would be blocked against the string. As it goes upward, the bottom part of the J is caught and the jack trips out from under the hammer allowing the hammer to fly freely towards the strings.

The strings, now vibrating, transfer their vibrations to the bridges, and the bridges do the same to the soundboard causing the air waves to vibrate and allow us to hear the piano.

As the key is being depressed, and the whippen is moving up with the back of the key, other piano parts attached to the whippens called a "spoon" in an upright piano pushes against the bottom end of the "dampers" which are involved with another lever system. The spoons cause the dampers to lift from the strings. When the key is released, the dampers return to their rest position stopping the vibrations of the strings.

In the grand piano action there are extra piano parts that are part of the damper lever system that is attached to the inside of the piano behind the action. When the parts of this system are pushed up by the very end of the key the dampers are lifted off the strings. Once again, when the keys are released, the whippens and dampers fall, shutting off the sound.

All of these piano parts must be adjusted so that all work in agreement with one another to produce the sound. Tolerances of 1/1000 of an inch make this playing mechanism, the piano action able to provide the finest nuances of the music being played.

Piano Keys

Only a small part of a piano key is visible from the outside and it extends deep inside the instrument so that the piano action can be initiated. On vertical pianos the smaller the piano generally the shorter the key, which can lead to leverage problems. In order to obtain the depth to which a key must be pressed down this leverage problem at the key can translate into problems with the geometry of the action. Better pianos have extra piano parts in the form of key weights made of lead inserted into the keys which influence how well a piano action works. Better pianos will have each key individually weighted so that the touch across the keyboard is completely consistent from note to note.

Hammers

Initially pianos used leather covered wooden hammers; presently, felt hammers are used and a hammer consists of a wooden molding covered with one or two and even three layers of compressed wool felt which vary in density.

The hardness of piano hammers affects the sound quality or tone. While hard hammers can produce sharp and clear tones, some would consider them perhaps hard and noisy. Softer hammers can produce more mellow or even dull tone. This is because hard hammers excite high frequency modes of a piano string’s vibration whereas the soft hammers are unable to do so.

Piano Pedals

Right Pedal – Also known as the Damper Pedal or Sustain Pedal is the most frequently used of the three pedals - many piano players never using the other two. Depressing the right pedal lifts the dampers from the piano strings; as a result, all the strings continue to vibrate irrespective of the note being played. When the pedal is returned to rest, the dampers do likewise.

Middle Pedal – Also known as the Sostenuto pedal, this pedal selectively sustains notes on a grand piano while all other sounds are stopped. In the vertical, this pedal tends to be a mute feature so that the piano is played extremely soft. This is so you don't disturb your neighbours - or perhaps your family.

Some uprights and most baby grands make use of a bass sustain in place of the Sostenuto pedal. While these uses for the middle pedal are fairly common now, manufacturers are known to have made rather innovative uses of the middle pedal such as a bar that would come down in front of the hammers in uprights. This bar would have pieces of leather in front of each hammer with a piece of metal inside. The sound produced would be a rinky tinky sound that was available in many pianos in the first years of the 20th century.

Left Pedal – Invented by Cristofori, the inventor of the piano. The left pedal shifts the keyboard so that all of the piano parts of the action, including the hammers, are able to strike only one or two strings for each note. Originally, the pedal was intended to strike only one string and was named the 'una corda’ pedal, which is Italian for ‘one string’.

Piano Strings

There are approximately 250 very strong steel wire 'strings' in a piano and it is the vibration of these steel wires that generates the sound. The thickness of the strings changes from the bottom to the top of the piano, but for each note (bass notes have 1 or 2 strings, the tenor two or 3 strings, and the treble 3 strings) they must be very consistent in thickness. Variations greater than 0.0003 inches (0.0076 mm) will give tonal distortion as well as drive your piano technician nuts.

Piano strings are made of high quality steel so they can endure years of high tension, blows and bending. The bass strings have their steel core wrapped in copper in order to lower the pitch.

Dampers

The dampers are the piano’s mechanism for stopping piano strings from vibrating. A damper is actually a small felted block that rests on a piano string in the grand or is held against the string in the upright by a spring to stop its vibration as soon as the key is released by the pianist.

Soundboard

If you look at the back of an upright piano, the big sheet of wood you see behind the posts (if posts are there) is the soundboard. On the grand, the soundboard can be seen underneath the strings and harp or cast iron plate.

Next time you are at a concert, be thrilled by the deftness of the pianist but don't forget to heartily thank the many minds and hearts behind the mechanical marvel that is a piano - from the design engineers, to the piano technicians that service them! Unless the thousands of piano parts work together well, the music quality will suffer.