Sentence:  For example, under God in the "mundus archetypus", we have nine orders of angels; under "coelum empireum", we have the sphere of fixed stars and the seven planetary spheres (each indicated by a symbol and by the note it plays in the music of the spheres), with earth making up the ninth item in the <WSD>enneachord</WSD> and "playing the lowest note among the elements" (terra cum elementis proslambanomenos); 
Meaning of the word marked with <WSD> tags:  A mystical chord or combination of nine entities that characterizes the "music of the spheres".