A stringed musical instrument has a sound chamber and a neck attached to the sound chamber. A fingerboard is attached along the neck. The musical instrument has an electronic device such as a chromatic tuner or a preamplifier, which is either mounted inside or on the exterior of the musical instrument. The fingerboard has a plurality of position markers which are flush with an edge face of the fingerboard. One or more of the position markers illuminates to display output from the electronic device. The position marker may either be the top of a light emitting diode attached to the electronic device, or the position marker may be the terminating end of a length of fiber optic cable, where the opposite end of the fiber optic cable abuts a light emitting diode mounted within the housing of the electronic device.