Piano pedals are foot-operated levers at the base of a piano that change the instrument's sound in various ways. Modern pianos usually have three pedals, from left to right, the soft pedal (or una corda), the sostenuto pedal, and the sustaining pedal (or damper pedal). Some pianos omit the sostenuto pedal, or have a middle pedal with a different purpose such as a muting function also known as silent piano.
The development of the piano's pedals is an evolution that began from the very earliest days of the piano, and continued through the late 19th century. Throughout the years, the piano had as few as one modifying stop, and as many as six or more, before finally arriving at its current configuration of three.