A string dampener for a musical instrument is disclosed for dampening extraneous string noise caused by sympathetic vibrations. The dampener includes an attachment apparatus that releaseably attaches the dampener to a portion of a stringed instrument. The dampener also includes dampening material to dampen string vibrations. An arm section is included that is rotatably coupled to the attachment apparatus and has the dampening material disposed on at least a portion of the arm section. The arm section is used to selectively engage and disengage contact of the dampening material with one or more strings of the stringed instrument by rotation with respect to the attachment apparatus. The string dampener affords quick attachment and detachment from a stringed instrument as well as easy engagement and disengagement of the dampener with the strings of an instrument with a requisite amount of pressure on the strings to effect proper dampening of sympathetic vibrations.