1. In a piano, a felt pad which mutes the string after it has been sounded and the piano key is then released. Also controlled by the sustaining pedal; when the sustaining pedal is "on," the dampers are lifted and the notes continue to sound. 2. Any device which mutes or dampens the sound of a percussion instrument. Dampers are used on bells, drums, and certain other effects in large orchestrions and organs. 3. The fine quill or wire mounted under the tip of a cylinder music box tooth, or mechanical device in a disc box, for the same purpose.