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PianoPedia: How It Works

The piano was originally named the “pianoforte,” because it was the first keyboard instrument that could play “piano” (soft) or “forte” (loud), depending on how the key is depressed. It was invented in 1709 by an Italian composer, Bartolomeo Cristofori (1651–1731).

Working in Florence, Cristofori built his pianoforte on the existing design of the harpsichord. He was hired by the Medici family to create a more expressive instrument. Harpsichord keys plucked the strings, influenced by a guitar-like instrument of the period, the lute. Thus, the harpsichord could only play one volume.

Cristofori replaced the plectrum mechanism of the harpsichord with felt hammers to strike the strings, enabling the volume to change. The thickness and length of the strings determine the higher and lower pitches, just like the short strings of a violin create higher pitches than the longer strings of the double bass. The strings are stretched over a soundboard for resonance.

The internal frame of the piano is made of cast iron. Various types of wood are used for the soundboard, internal components, and keys. Today’s piano keys are often plastic, which don’t yellow with age like the older ivory keys. Piano strings are generally made of steel.

There are three pedals on the piano. The one on the far right is the damper pedal. Played by the right foot, it lifts the dampers (felt pads that stop the vibration of the strings) off of the strings so that there are more vibrations as the notes ring freely. This helps to produce full, ringing, rich sounds.

The middle pedal is called the sostenuto pedal and is played by the left foot. It lifts the dampers off the strings but only for the first note or chord in a passage. This allows the first note or chord to resonate while the pianist plays other notes. This is the least used of the three pedals.

The left pedal is called the soft pedal or una corda (“one string”) and is also played by the left foot. It shifts the entire keyboard so that the hammers do not strike all the strings on each note, creating a softer sound and more muted color.

Today there are two primary types of pianos, upright pianos in which the strings run vertically and grand pianos in which the strings run horizontally.

The piano has a wide range. The 88 keys of a standard piano keyboard span over seven octaves. The piano is a versatile instrument, capable of playing melody and harmony, and many different styles—jazz, classical, boogie-woogie, gospel, rock and roll, and more.

The piano is a member of the string family since the sound is created by striking strings, but it’s also a member of the percussion family, because the player “hits” or presses the keys.