GlossaryBelow is a short glossary of terms you’re likely to encounter if you are thinking of buying a new piano, or are considering having your existing instrument reconditioned. I hope the definitions will prove helpful. When you’ve finished reading, you’ll be ready to try out my Piano Parts word search!
Action: a complicated mechanism, made up of levers and balances, which transmits the physical movement of a player’s fingers from the keys to the hammers. An action can comprise up to eighty individual components!
Agraffe: a brass guide which the strings of the middle and bass sections pass through, to make a termination point. (An agraffe ‘V bar’ is used for the treble strings.) Strings vibrate freely between the agraffe and front bridge pin.
Backcheck: a felt or leather-covered catcher, fastened to the end of the piano key with a wire. The backcheck catches the hammer as it rebounds, preventing it from bouncing around and helping the action to recover quickly.
Bridge: a narrow piece of wood glued to the soundboard. Usually made of a hardwood such as maple, the bridge allows the strings to transfer vibration to the soundboard. Each string is held in place with two metal bridge pins.
Damper: a small, felt-covered piece of wood which rests against the strings. Dampers are lifted from the strings just before a key is struck, and returned when it is released. This stops their vibration, and silences each note.
Escapement: a mechanism that enables the hammer to ‘escape’ after striking, so the strings can vibrate freely. Double escapement allows a hammer to strike again, without waiting for the key to rise to its normal position of rest.
Fallboard (or nameboard): the hinged part of the case, which covers the keys. The maker’s name is usually inlaid, often in brass. If you get brass polish where it shouldn't be, stains can be removed using beeswax and a soft cloth!
Grand: a grand piano has its strings and soundboard oriented horizontally. Grands are categorized according to length (measured from the tail to the front of the keyboard trim), as baby, boudoir, professional, concert and so on.
Hammer: a hammer is made of felt, formed around a wooden mould. To achieve the shape, many tons of pressure is applied. For every note played a hammer must move five times as far, and four times as fast, as your finger!
Keyboard: the 88 keys are laid out on three rails, known as the keyframe. Each key pivots on a pin driven into the centre rail. Paper bushings control the height of the keys, and how far they travel when depressed (the ‘key dip’).
Lyre: on a grand piano, the removable part of the case that connects the pedals to the underside of the instrument (sometimes fashioned in the shape of a lyre). The pedals are held in a pedal box at the bottom of the lyre.
Pedals: levers controlled by the feet, which sustain all of the notes being played (the right, or sustain, pedal) or individual notes (the middle, or sostenuto, pedal), and soften the piano’s tone (the left, or una corde, pedal).
Pinblock (or wrestplank): a solid piece of wood which holds the tuning pins in place. The pinblock must withstand the cumulative force of all of the strings pulling on the tuning pins, perhaps as much as 30 tons of tension!
Plate: the metal structure to which the strings are attached, which in turn is bolted to a 400lb cast iron back frame. The back frame holds the tension of the strings; the stronger it is, the longer the piano will stay in tune.
Rebuilding: replacing parts, in an effort to restore a section of an instrument to its original condition. The parts most often replaced include hammers, keys, strings, tuning pins and the felts and leathers of the action.
Reconditioning: a general term for cleaning, adjustment and repair. Reconditioning can be extensive, or limited to a section of the piano. Individual parts are replaced as necessary, but not to the extent of rebuilding.
Regulation: the process of adjusting the action. Some parts push or pull against each other; some are connected by wires and springs. To regulate a part is to position it correctly, and time its motion with other moving parts.
Soundboard: a bowed wooden surface over which the strings are stretched. The soundboard acts as a resonator, and is essential to good tone: when you listen to a piano, it is largely the soundboard you are hearing.
String: a thin, steel chord. In most instances a hammer strikes three strings for each key, causing the vibrations that become the sound of the piano. The thicker the string, the more slowly it vibrates and the lower the tone.
Tone: a sound of definite pitch and quality, as distinct from noise. The tone of a note is determined by how hard it is played, and changes during the time that it is held. A beautiful tone on the piano means a beautiful sound!
Tuning: a tuning hammer (also known as a tuning wrench) is used to turn the tuning pins. This alters the tension of individual strings, in order to change their pitch and timbre and align the intervals between their tones.
Tuning Pin: a threaded steel peg, driven like a nail into the pinblock. Each string is passed through a tuning pin and wound around it, to form a coil. When a pinblock loses its grip, strings can be re-pinned using larger pins.
Upright: also known as a vertical piano, the strings and soundboard are oriented vertically. Uprights are categorized according to height (measured from the floor to the lid) as full upright, studio upright, console, and spinet.
Voicing: the process of obtaining a particular quality of tone, by hardening or softening the hammer felts in order to change their density. Voicing ensures a smooth, consistent progression of tone over the entire range of strings.
Wippen: a hinged lever housed above the key, which transfers mechanical advantage from the key to the hammer. The wippen holds a spring-loaded repetition lever in grand pianos, and the backcheck in upright instruments.