This unique sundial by the Tauber River is designed in the shape of a harp. The two shadow casters are imaginatively shaped like the strings of a concert harp, giving the sundial a musical touch. The sundial features two separate dials: an east-facing dial that shows the time in the morning and a west-facing dial that displays the time in the afternoon and evening. Both dials indicate Central European Standard Time (CET) at the top and Central European Summer Time (CEST) at the bottom, depending on the position of the sun.

In the center of the sundial is a square plate with a small hole. At solar noon, exactly at 12:00 PM local true time (LTT), the sun shines through this hole, creating a point of light. When this light hits the photo cell beneath it, a tape recorder is activated, and the harp concert "Also sprach Zarathustra" by Richard Strauss is played.

The innovative design of this sundial, which is both aesthetically and functionally impressive, reflects the diversity and creativity found in many sundials around Röttingen.