Pianos are short for pianofortes, which are so named because of their dynamic range. The pedals, the metal frame, the soundboard and bridges, the action, the casing, and the strings are the six main mechanisms that make pianos work in traditional playing. For each pitch, there are three strings for the treble notes, two for the tenor notes, and one for the bass notes.
The keys, hammers, and hammer mechanism are all involved in the action. When you press a key, the hammer mechanism moves and strikes the strings. The vibrations of the strings are picked up the bridges and carried to the soundboard. The metal frame keeps the strings taut, while the casing protects them.
On the sound of pianos, the three standard pedals have three different effects. The left pedal, also known as the soft pedal, has several functions. It may, for example, adjust the hammer to the side so that it only strikes two treble strings and one tenor string, therereducing the sound, or shift the hammer closer to the strings, thereshortening the hammerstroke. The right pedal, also known as the loud pedal, de-emphasizes the strings, allowing them to vibrate freely. The dampers are also affected the middle pedal, with the dampers being raised only for the notes that are being played when the pedal is engaged.
When a performance requires a prepared piano, pianos can be used in a variety of ways. Prepared pianos are modified in ways that allow them to exploit a wide range of timbre possibilities that would otherwise be unavailable in performance. The strings of prepared pianos can be plucked, scraped, or struck directly the performer with their hands or an implement. The effects can be changed inserting material, such as paper, between or among the strings.
Partially dismantling prepared pianos can alter the resonance space. Other instruments can be played in such a way that their sound reverberates through the piano strings, causing sympathetic vibrations. Alternatively, the casing or metal frame could be struck, producing a variety of sounds.