OMAHA, Neb. — A remake of “Empire State of Mind” with lyrics about Berkshire Hathaway, greeted shareholders this morning. (I’m not sure if it was actually sung by Jay Z and Alicia Keys, but it sure sounded like it. We’ll try to get the lyrics for you at some point.) The song is a throwback — fitting for a Berkshire Hathaway annual meeting, which is the very definition of old-school.