Piano
The damper pedal (also called the sustain pedal) is the pedal on the right, and the one that is used most often. For this reason, it is often called just "the pedal". It is pressed with the pianist's right foot, and makes the dampers (which look a bit like the hammers) that usually rests on the strings come off, so the strings are free to vibrate. As long as the pianist holds this pedal down, the notes he plays will keep on sounding even when he takes his fingers off the keys. Some other strings will also vibrate very lightly (this is called “sympathetic vibration”), which makes the sound smoother and richer. Pianists have to learn how to use this pedal well. This will depend on such things as the style of the music, the size of the piano, the size and the acoustics of the room in which the instrument is in.