I claim the ornamental design for a sound hole for a stringed musical instrument, as shown and described.
FIG. 1 is a top plan view of the sound hole for a stringed musical instrument in accordance with my new design;
FIG. 2 is a top plan view of an alternate embodiment of the sound hole for a stringed musical instrument in accordance with my design, which is a mirror image of the sound hole for a stringed musical instrument shown in FIG. 1;
FIG. 3 is a top plan view of the sound hole for a stringed musical instrument in accordance with my design, shown as it might be positioned in one embodiment of a stringed musical instrument; and,
FIG. 4 is a top plan view of the sound hole for a stringed musical instrument in accordance with my design, shown as it might be positioned in another embodiment of a stringed musical instrument.
The broken lines in FIGS. 3 and 4, showing a stringed musical instrument, as shown for the purpose of illustrating environmental structure, and form no part of the claimed design.