Piano
The piano is a musical instrument, one of the most popular in the world. Used mostly in classical music, solo performances, backing music, ensemble use, dance music, hip-hop and much more. Although the piano isn’t portable and often really expensive, the piano’s wonderful sound has made it one of the world’s most familiar musical instruments.
Sound-
Pressing a key on the piano’s keyboard causes a felt-covered hammer to hit steel strings. The hammer rebounds, allowing the strings to continue vibrating. These vibrations are then transmitted through a bridge to a sounding board that more efficiently couples the acoustic energy in the air. When the piano key it released a damper stops the strings from vibrating. The musical terms "piano" and "forte" mean "quiet" and "loud," and in this refers to the variations in volume of sound the instrument produces in response to a pianist's on the keys, the greater a key press's velocity, the greater the force the hammers hit the strings with, and the louder the note produced. Longer pianos with longer strings have larger, richer sound and lower. Pianos with shorter and thicker strings, i.e. small pianos with short string scales, have more inharmonicity. The greater the inharmonicity, the more the ear perceives it as harshness of tone. The relationship between two pitches, called an interval, is the ratio of their absolute frequencies. Two different intervals are perceived as the same when the pairs of pitches involved share the same frequency ratio. The easiest intervals to identify, and the easiest intervals to tune, are the ones that are just, meaning they have a simple whole-number ratio.
Types-
Modern piano come in two basic figures, the grand piano and the upright piano. Some other types of pianos are Electric Pianos, Prepared piano, Yamaha Clavinova, Silent piano and the transposing Piano.
The Grand Piano-
In grand pianos, the frame and strings are horizontal, with the strings extending away form the keyboard. The action lies beneath the strings, and uses gravity as it means to return to a state of rest. There are many sizes of grand piano. The Concert Grand Piano 9between about 2.2m and 3 m/9.84 feet long). The Parlor Grand or Boudoir Grand (about 1.7 m to 2.2 m) and the smaller Baby Grand (around 1.5 m)

History-
The word piano is a shortened form of pianoforte, the Italian word for the instrument is "gravicembalo col piano e forte"
Pedals-
Pianos have pedals, or some sort of close