Instrument
Piano
Struck strings and a full harmonic range, in a single instrument played by one person.
The piano produces sound by striking steel strings with felt-covered hammers when a key is pressed - visible in the image above, where each key's hammer sits ready against its own set of strings. That mechanism, invented in Italy around 1700, let players control both loud and soft dynamics through touch alone (the name "pianoforte" literally means "soft-loud"), something its harpsichord predecessor couldn't do.
How it works
Pressing a key sets off a lever system called the action, which flings a hammer up against the strings and lets it fall away instantly so the strings can ring. At the same moment a felt damper lifts off the strings; when the key is released, the damper drops back and silences the note. How hard the key is struck controls how fast the hammer travels, and so how loud the note is.
A modern piano has 88 keys, covering more than seven octaves - a wider range than any instrument in the orchestra. Most notes have two or three strings tuned in unison for a fuller sound, and the strings are stretched across a cast-iron frame that holds a combined tension of many tons.
Most pianos have three pedals:
- The right-hand sustain (or damper) pedal lifts all the dampers, so notes keep ringing after the keys are released - the source of the piano's rich, blended sound in Romantic music.
- The left-hand soft pedal makes the tone quieter and gentler.
- On a grand, the middle pedal sustains only the notes being held when it's pressed; on many uprights it's a practice mute instead.
A grand piano lays its strings horizontally, while an upright stands them vertically to save space - the grand's action is more responsive, which is why concert pianists play grands.
A solo instrument, an accompanist, an orchestra
Because a single player commands the instrument's entire range - bass notes, melody, and harmony all at once - the piano can function as a complete musical world on its own: solo repertoire, accompaniment for singers and other instruments, and the core instrument of the piano concerto and piano sonata alike. Its versatility has made it the instrument most commonly used for composing and teaching music generally, not just for performing it. In the orchestra itself, though, the piano is usually a guest soloist rather than a regular member.
How the piano developed
Bartolomeo Cristofori built the first pianos in Florence around 1700. The pianos Mozart knew - now usually called fortepianos - were lighter, quieter instruments with a range of about five octaves. Beethoven wrote music that strained against the limits of the instruments of his day, and makers kept extending their range and strength to keep up.
The 19th century built the modern instrument: iron frames that could carry heavier strings, a repeating action that allowed fast repeated notes, and a louder, richer tone that could fill a concert hall. It was the age of the piano virtuoso - Liszt is often credited with inventing the solo recital - and also of the piano at home, as a parlor piano became a fixture of middle-class households.
Essential piano music
- Bach - The Well-Tempered Clavier: written for the keyboards of his day, now a cornerstone of piano study.
- Beethoven - the 32 piano sonatas, including the "Moonlight" and "Pathétique."
- Chopin - nearly everything he wrote: nocturnes, etudes, ballades, waltzes.
- Schumann - Kinderszenen ("Scenes from Childhood").
- Debussy - Clair de Lune and the Preludes.
- Rachmaninoff - Piano Concerto No. 2.
Where to start listening: Beethoven's Moonlight Sonata and Chopin's Nocturne in E-flat major both show the instrument's expressive range at its most immediately accessible. For the piano as a dazzling showpiece, try Liszt's Hungarian Rhapsody No. 2.