I would say don't make it obtrusive in any way. If it is an opener and it doesn't last too long make it can be stirring and noticeable. If there are several tunes try to blend with the subject in hand like title that refer to the article like a "Nut Brown Bowl" "Little Brown Jug" sort of "in" jokes, some folks will get them . I would advise putting your credits in the "About" box so that you can claim it is out of copyright (assuming it is) - it's the old ruse - get your story in first, don't wait for someone else to establish the claim. Try and get someone to write a piece for you and give them the credit. If you write your own tunes it is a very smart way of establishing copyright. Only liars can gainsay you.