A tuning device for a stringed musical instrument comprising a socket to receive a peg of the instrument, a shaft rotatably connected to the socket, a motor to induce rotation of the shaft, a first gear to reduce the shaft rotation and increase torque from the motor, the first gear being engaged to the motor, a second gear to exponentially reduce the reduced shaft rotation, the second gear being engaged between the shaft and the first gear, a cutter to trim a string of the instrument, and a housing to cover and protect the shaft, the motor, and the gears, where the cutter is attached to the housing opposing the socket.