The following are some terms relating to pianos:
Action: A piano’s action is its entire working inner mechanism. Through the use of several thousand moving parts, the action produces sounds through the beating of hammers on strings. There are many parts of the action that can be adjusted to alter the musical temperament of the instrument.
Agraffe: Agraffes are little brass piano parts that have holes in them. The instrument’s strings go through the holes in the agraffe. This keeps the strings properly spaced out inside the instrument. Not all pianos have an agraffe.
Bridge: The bridge of a piano is between the soundboard and the strings of the piano. The wooden bridge is what the strings’ vibrations move along to reach the soundboard, creating audible notes.
Bushing: A piano’s bushing is a piece of fabric that protects the metal or wood of a piano from the piano’s metal hardware.
Damper: A piano’s damper is connected to the lever assembly. It is a felt cushion that pianist can engage – usually through the use of a pedal – to instantly end string vibration.
Hammer: The hammer is the part of a piano that produces music by beating on the strings. Hammers are small mallets made from a wooden base encased in heavy felt.
Hammer Filing: Piano hammers must be maintained to continually produce notes that are clear and accurate. Hammer filing can also involve removing worn out felt from the hammer. Hammer filing is part of piano tuning since it can alter the musical qualities of the instrument.
Hitch Pin: Piano strings are kept in place by hitch pins. These are not to be confused with the tuning pins, which can be adjusted to alter the notes each string produces.
Sympathetic Vibration: Sympathetic vibration is when strings next to a struck string also vibrate from the impact. This is a natural occurrence.
Voicing: Voicing is a type of piano tuning that is accomplished by altering the hammers to produce desired note pitch, uniformity, and other musical specifications. Voicing can be done by changing a hammer’s shape, density, and other physical properties.