Hi -- I'm the real estate guru -- in my experience insurers will cover anything and everything. (I knew a guy who collected, I kid you not, corkscrews).

In addition to the deductibles problem Dave pointed out, though, you've got a valuation problem. You'll have to work with the insurance company to detail not only the collection, but the condition of the collection -- for something smaller, they'll probably let you self-declare, but with a large collection, you'll have to work with them to detail what you own and how often it has been played, whether the covers are marked, etc.

That said, if it's precious to you, insure it. I like Dave's approach of a rider on your homeowners' -- check that out.