Die Hard (1988) is a really well made film. Lots of subtle little things set up at the beginning that pay off at the end (Holly's Rolex was great) but I didn't remember that the score was built around Beethoven's Ode to Joy, which is first heard playing at the Christmas party.
The Nakatomi Corporation is a Japanese company, so of course Ode to Joy was playing at the Christmas party because it's a Christmas carol. Take that, "Die Hard isn't a Christmas movie!" people.