A stringed musical instrument having a back, a side and a first sound board that form a sound box. The back, side and first sound board further define an enclosed resonant cavity within the sound box. A bridge is positioned on the surface of the first sound board on a side of the hole opposite a neck for attaching strings. A second sound board is positioned in opposition in a spaced relation to the first sound board within the cavity of the sound box, sandwiched in spaced relation between the back and the first sound board. The first and second sound boards each having a hole formed therein. The bridge further includes a sound transfer bar vertically disposed between the first sound board and the second sound board. The sound transfer bar effectively transfers vibrations from the first sound board to the second sound board and further equalizes any upward or downward pull by the bridge caused by the tension of the strings.