Since being used to commemorate the funerals of the likes of FDR, JFK and Albert Einstein, Samuel Barber's famous, lush tearjerker Adagio for Strings has become an unnoficial anthem of communal mourning. But the work has also elicited some very different emotions by appearing in some unexpected places, like an episode of Seinfeld or the floors of a dance club. Take a deep dive into the piece itself.