Grand piano

Piano

A grand piano (left) and an upright piano (right)
Keyboard instrument
Hornbostel–Sachs classification	314.122-4-8 (Simple chordophone with keyboard sounded by hammers)
Inventor(s)	Bartolomeo Cristofori
Developed	Early 18th century
Playing range

The piano is an acoustic, stringed musical instrument, in which the strings are struck by hammers. It is played using a keyboard, which is a row of keys (small levers) that the performer presses down or strikes with the fingers and thumbs of both hands to cause the hammers to strike the strings. Invented in about 1700 (the exact year is uncertain), the piano is widely employed in classical, jazz, traditional and popular music for solo and ensemble performances, accompaniment, and for composing, songwriting and rehearsals. Although the piano is very heavy and thus not portable and is expensive (in comparison with other widely used accompaniment instruments, such as the acoustic guitar), its musical versatility (i.e., its wide pitch range, ability to play chords with up to 10 notes, louder or softer notes and two or more independent musical lines at the same time), the large number of musicians and amateurs trained in playing it, and its wide availability in performance venues, schools and rehearsal spaces have made it one of the Western world's most familiar musical instruments.

An acoustic piano usually has a protective wooden case surrounding the soundboard and metal strings, which are strung under great tension on a heavy metal frame. Most modern pianos have a row of 88 black and white keys, 52 white keys for the notes of the C major scale (the notes C, D, E, F, G, A and B) and 36 shorter black keys, which are raised above the white keys, and set further back on the keyboard. This means that the piano can play 88 different pitches (or "notes"), going from the deepest bass range to the highest treble range. The black keys are for the "accidental" notes (F♯/G♭, G♯/A♭, A♯/B♭, C♯/D♭, and D♯/E♭), which are needed to play in all twelve keys. Most keys have three strings, except for bass notes which only have one or two. The strings can be sounded when the keys are pressed or struck, and silenced by a damper when the hands are lifted off the keyboard. The notes can be sustained, even when the keys are released, by the use of pedals at the base of the instrument. The sustain pedal enables pianists to play musical passages that would otherwise be impossible, such as sounding a 10-note chord in the lower register and then, while this chord is being continued with the sustain pedal, shifting both hands to the treble range to play a melody and arpeggios over the top of this sustained chord. Unlike two of the major keyboard instruments that were widely used before the piano, the pipe organ and the harpsichord, the weight or force with which a performer presses or strikes the keys on a piano changes the dynamics and tone of the instrument's sound.