Abstract: A device for adjusting the pitch and quality of the sound produced by a diaphragm-type game call. Two embodiments are presented, which may be built by the manufacturer into a conventional call or clipped onto a pre-existing call by the hunter. The invention comprises a tuning bar which extends across the width of the diaphragm. The tuning bar may be slid along the length of the diaphragm, from the vibrating edge inward toward the fixed supported end. In the preferred embodiment, the tuning bar has a tab or "step" which extends downward toward the diaphragm, acting as a fret or stop and modifying the air flow over the diaphragm, allowing greater variations in sound.