“This geometric construction of the traditional instrument the oud, shows equal 7 divisions, showing the seven sounds of Sur Sa Re Ga Ma Pa Dha Ni Sa, or solfège syllables (do, re, mi, fa, sol, la, ti),The words were originally written by Paulus Diaconus in the 8th century. They translate as:

So that your servants may, with loosened voices,
Resound the wonders of your deeds,
Clean the guilt from our stained lips,
O St. John. the number seven is also used to show the seven levels of the journey of the soul.”