We bet you weren't expecting to hear Beethoven in a blockbuster (for that matter, we don't think Beethoven was either). But there he is—playing at the cocktail party as Hans and his henchmen emerge from the elevator to wreak havoc. "Ode to Joy" is used in-scene here—it's being played by a string quartet at the party—and Michael Kamen, Die Hard's screenwriter, echoes the melody from Beethoven's 9th Symphony in other key scenes on the soundtrack.
When Hans Gruber exits the Pacific Courier truck and enters Nakatomi Plaza, we hear the notes played on some rather menacing strings. Then, as the scene unfolds and the "terrorists" begin their well-coordinated takeover of Nakatomi Plaza, the score melds phrases of "Winter Wonderland," "Singin' in the Rain" (which Theo also happens to whistle as he takes control of the building's tech hub), and "Ode to Joy" together, to lend the movements of the baddies a sense of jaunty grace.
Known for his action scores (the Die Hard franchise and the Lethal Weapon franchise, to name a few), Michael Kamen uses these pop cultural musical allusions to imbue the score with a levity that director John McTiernan requested. Not wanting the summer blockbuster to be too much of a violent bummer, he thought that strategic use of well-known classical music might help lighten the mood. He continues this pattern throughout Die Hard. Though it's subtle, you can hear these musical phrases again and again if you know what to listen for.
He also deftly twists those musical phrases to fit the mood of the scene. When Hans and Theo first look at the vault, we hear "Ode to Joy" in an ominous, slow tone. But later, when they finally open the vault, we hear the original arrangement of the tune—triumphant, fast, and of course joyful.
On the Radio
Apart from the score, Die Hard also makes use of songs-in-scene—in other words, songs the characters can hear just as well as we can. We get most of these courtesy of Argyle's limo radio, and they make for several moments of comic relief. When Argyle first pops in a tape, it's Run-D.M.C.'s "Christmas in Hollis." "Don't you got any Christmas music?" McClane asks skeptically. "This is Christmas music," Argyle replies.
Later, Argyle's car radio is used for even greater comedic effect. Argyle spends much of the first half of the movie in ignorant bliss, jamming to Stevie Wonder's "Skeletons" in the backseat with McClane's teddy bear. Even when Al Powell goes speeding by in the rearview, getting shot up by a machine gun and screaming bloody murder, Argyle's just too into the song to notice. This is made all the more hilarious by the fact that earlier, as he watches Powell circle the building's driveway in a police cruiser, McClane asks, "Who's driving this car, Stevie Wonder?"
It's Christmas in July, and the folks behind Die Hard are not about to let you forget it. From the sleigh bells that pepper the soundtrack to John McClane whistling a few bars of "Jingle Bells" as he enters Nakatomi Plaza, to Al Powell singing "Let it Snow" as he fills his arms with Twinkies, the notes of Christmas are everywhere in this movie.
Die Hard saves the most memorable use of Christmas music for the final scene. As Holly and John pile into the back of Argyle's limo and drive off into the… middle of the night, we hear Vaughn Monroe's version of "Let it Snow," and the credits roll. Of course, it doesn't snow in L.A., so they'll have to make do with all the paper drifting down from the rubble of Nakatomi Plaza. How cozy.
Fun fact: When Al Powell shoots Karl, taking the villain down for once and for all, the score that plays in the background is actually an unused bit from Aliens.