Adding this type of circular decoration to a lute rosette brings about another aesthetic detail and in my opinion acts as a frame for the rosette pattern. As an instrument maker I find that the circular decoration is to the lute rosette what a frame is to a picture; it brings some sort of closure and emphasizes the artwork in the center.
By the way, this rosette now visually deviates from the broken top which is to be replaced. However, the client agreed that an “improvement” of the aesthetics is deemed historically justified, since the new rosette is now strictly based on the suspected origin of this design – a lute by Wendelin Tieffenbrucker dated “end of 16. century”. The technical drawing I used as a guideline for this design is marked “Nr.(8439, C40) 39” and is found in the collection of the KHM Vienna.