What do the piano pedals do? Pianos, keyboards and digital pianos can have one to three foot pedals that perform various musical functions. The most important pedal is the Damper or Sustain pedal, usually found on the furthest right on acoustic instruments, and the only one for single pedal keyboards. The Damper/Sustain pedal controls how long the notes can be heard after playing them. The second most important pedal is the Soft pedal, otherwise known as the Una Corda. This controls how soft the piano sounds, and is usually the pedal furthest to the left on acoustic pianos. The third pedal – usually the middle one – varies in function, depending on the type of piano. On grand pianos, the middle pedal is known as a Sostenuto pedal. This pedal only holds notes that have been “locked” with the fingers, keeping the other notes free to be controlled by the other pedals or with the fingers alone. On upright pianos, the middle pedal is usually the practice pedal, moving a piece of felt between the hammers and strings to produce a muted sound, perfect for keeping the piano quiet and not disturbing others