Abstract: Mechanism that converts a rotary knob (potentiometer) motion on an electric guitar, into a linear sliding motion. The sliding motion can be easily manipulated by the strumming or picking hand of the musician while simultaneously playing the instrument. This mechanism allows an electric guitarist to make sweeping motions with the picking hand while playing to create musical effects with the tone control known as a “wah wah” sound, or “boo wah” sound, and the volume control to create effects known as “volume swells” or volume “tremolo”. The way this mechanism works is by pushing and pulling on a finger loop that is positioned for easy access, the finger loop is fastened to a trolley that has two bearings on it that roll in a track in the main body. The trolley has a gear rack fastened to it and that gear rack rotates a gear that is fastened to the knob stem on the potentiometer, and the action will rotate the potentiometer to its full range.