Abstract: A stringed instrument, such as a guitar, has a finger-board, a headstock located at one end of the finger-board, and a plurality of machine-heads mounted on the finger-board for adjusting the tension of the strings. Each machine-head has a rotatable winding peg for winding a respective string to be adjusted, and a rotatable adjusting handle coupled to the winding peg for rotating the peg. The axis of rotation of the adjusting handle is inclined rearwardly relative to the plane of the finger-board and is non-parallel to the axis of rotation of the winding peg. In addition, the axis of rotation of the adjusting handle is inclined at an acute angle relative to a perpendicular to the longitudinal axis of the instrument and generally toward the opposite end of the instrument, in order to facilitate the ability of a person playing the instrument to locate and adjust each machine-head.