Presumably, being in show biz, Mr. Shakespeare did have opportunities to consort with musicians.
I'm reminded of the "sea metaphors" that are supposed to mark Bill Ayers contribution to Ogama's memoir -- as though Obama or some other ghost writer couldn't have come across nautical imagery on their own.
Whether or not Shakespeare read Dante is a question that's been much discussed. I wonder if it's not a little like the case of Shakespeare and ourselves -- even if we never actually read Shakespeare we use phrases that he (or she or them or it) created. Possibly a few Dante phrases made their way from Italian to English usage and ended up in Shakespeare's plays.
I remember that discussion well. It wasn't that Obama couldn't come up with it on his own, it's that he had shown no evidence of using it, either before or after. Ayers did use nautical references throughout his writings, and was a merchant seaman for awhile after college.
That's Occam's Razor territory.
That's what is so intriguing about this article. There are many things that were written about that this author implies needed special knowledge by the author (shibboleths), such as fluency in Hebrew. And then there are the names...
-PJ