The three pedals on a keyboard are the sustain, sostenuto, and soft pedal. The sustain pedal is the most commonly used of the three, and it sustains all the notes that are being played when it is pressed down. The sostenuto pedal sustains only the notes that were being played when the pedal was pressed down, while the soft pedal lowers the volume of the notes being played. All three pedals can be used together to create different sound effects.