Abstract: An improved tremolo device for a stringed musical instrument provides a fixed plate attached to the body portion, a fixed gear rack with teeth, and a movable plate that is slideable with respect to the fixed plate and has a bridge member. A pinion gear having teeth around the circumference thereof is provided to mesh with the teeth of the fixed gear rack and to move in unison with the movable plate. A lever is attached to the pinion gear for rotating the pinion gear to change the tension on the strings. The fixed plate has a slot or groove in the face thereof opposite the body, and the movable plate has a slot or groove in the face thereof opposite the fixed plate to form one or more cavities in which anti-friction bearings are encased. In the operation of the tremolo device of the invention, tension in the strings is decreased by depressing the lever which causes pinion gear to rotate, thereby driving the movable plate to cause the tremolo effect when the musical instrument is played.