The piano is a keyboard instrument that produces sound when its keys are
depressed, through engagement of an action whose hammers strike strings.
Modern pianos have a row of 88 black and white keys, tuned to a
chromatic scale in equal temperament.
The invention of the piano is credited to Bartolomeo Cristofori
(1655–1731) of Padua, Italy, who was employed by Ferdinando de' Medici,
Grand Prince of Tuscany, as the Keeper of the Instruments.