Relative harmonic dynamic pitch control device and system

A stringed instrument, comprising:

• a neck;
• a body, the body defining an interior cavity;
• and
• a tremolo comprising a tremolo frame, a tremolo lever, and one or more tremolo cams,
• wherein the one or more tremolo cams comprise, in combination, a plurality of laterally spaced-apart curved string contact surfaces at positions and at a spacing corresponding to a string positions of a plurality of strings for the stringed instrument, the one or more tremolo cams being disposed at a central portion of the body, each of the plurality of string contact surfaces having a lateral width greater than a width of a corresponding stringed instrument string,
• wherein the tremolo lever is rotatably mounted to the tremolo frame to rotate about an axis of rotation, the tremolo lever having an upper portion and a lower portion, the upper portion being adjacent the tremolo frame and being rotatably connected thereto by direct or indirect connection to the tremolo frame, the lower portion extending downwardly away from the upper portion and into the interior cavity defined within the body of the stringed instrument, the lower portion of the tremolo lever comprising, at or near a distal portion of the lower portion, one or more string retention structures configured to secure end portions of stringed instrument strings,
• wherein the upper portion of the tremolo lever further comprises a first mechanical connector to receive, or to removably receive, a mating second mechanical connector at a first end portion of an outer lever arm,
• wherein forces applied to the lever arm by a user to rotate the tremolo lever about the axis of rotation in a first direction of rotation displaces the distal portion of the tremolo lever in a first direction to increase a tension in, and a pitch of, strings secured at the distal portion of the tremolo lever via the one or more string retention structures by an amount corresponding to a first angle of rotation in the first direction of rotation, and
• wherein forces applied to the lever arm by a user to rotate the tremolo lever about the axis of rotation in a second direction of rotation displaces the distal portion of the tremolo lever in a second direction to decrease a tension in, and a pitch of, strings secured at the distal portion of the tremolo lever via the one or more string retention structures by an amount corresponding to a second angle of rotation in the second direction of rotation.