One last thing then before I go until early April (see my thread on the matter for more on that): the line is:
Upon my great neck I can always be found in nature's most wondrous diadem crowned.
This refers to the great neck of a fiddle having upon it horse hairs for strings, a horse's mane being nature's most magnificent of crowns for its creatures. (Its prehensile strength is just astounding, and it's so gorgeous, and makes wondrous music.) Make sense now?