Solid wooden frame which supports the whole construction of the piano. It especially offers resistance to the bending forces which result out of the string tension (approx. 180,000 newton!).
The dampers, in simple terms, are wooden levers with a felt head which rest on the strings when not played. When a note is played, the damper lifts off the string just before the hammer strikes the string. As long as the key is depressed, the damper will not touch the string. After letting go of the key, the damper returns to the string and cuts off the sound. The right pedal raises all the dampers simultaneously.
Anchored in the iron frame, this is a device which holds the end of the string. The other end is wound around the wrest pin. The string is tuned by turning the wrest pin.
The iron frame supports, together with the wooden back-frame bracing, the tension of the 220 strings. This tension is between 15 and 20 tons. The hitch pins for fastening the strings are anchored in the iron frame, which is bolted to the wrest plank and the soundboard brace.
Ivory keys, ebony
Keys used to be made of ivory: a frequently held opinion. It is not true! Keys have always been made of wood; only the surface was covered with a thin layer of ivory. Meanwhile, to protect elephants and for other reasons, other materials are employed. It has been attempted, not always successfully, to imitate the touch properties of ivory. Black keys were formerly made of ebony; nowadays, plastics are increasingly in use. Worn or yellowed key coverings can be restored and bleached so as to look new.
A feature of the action which enables the hammer to fall back several millimetres after striking the string, although the key is still depressed, thus enabling the string to vibrate freely.
Every upright and grand has two pedals. Some have three. The right (or sustaining) pedal lifts the dampers allowing the struck strings to sound freely. The left (or soft) pedal enables softer playing. This is achieved in two different ways : in a grand, the entire action shifts so far sideways that, with notes consisting of three or two strings, one of the strings is no longer struck. In an upright, the hammers tilt towards the strings, reducing their travel and therefore their momentum.
The function of the middle pedals varies from instrument to instrument. In a piano it usually activates the moderator: A felt is moved between the hammers and the strings and reduces the loudness of the sound.
The soundboard is a wooden panel which transmits the string vibrations to the air, thus making the sound audible. The strings are stretched across a bridge which transfers the vibrations to the board. Soundboards are mostly made of timber from slowly growing, mountain spruce trees from high altitudes.
Voicing (or toning)
The hammer felt is pricked with needles to regulate the degree of hardness, thus influencing the tone colour and volume.
A cylindrical, metal part with a square head. The greater part is inserted in the wrest plank. The string is wound around the visible end of the pin. Turning the pin lowers or raises the string tension and the piano can be tuned.
A solid wooden plank in which the tuning pins are driven. The strings are attached to the pins. In an upright the wrest plank is attached to the back frame, and in a grand to the outer rim.