Movies need music, or at any rate it's hard to think of ones that don’t. Where would Quentin Tarantino be without Seventies pop, or Wes Anderson without the British Invasion, or Steven Spielberg without John Williams? Film noir isn't really film noir unless you can hear the dissonant strings, the off-kilter piano, the wail of the distant sax.

But sometimes, filmmakers feel the need to reach back a bit further and use the classics. At its laziest, it's a cheap way of introducing instant class or empty pathos into a soundtrack: there are countless straight-to-DVD Barbie movies in which one or other of JS Bach's Brandenburg Concertos is used to signify grace and refinement, while at the other end of the quality scale, Martin Scorsese's use of the final chorale from Bach's St Matthew Passion to accompany the opening titles of Casino was trying a bit too hard to make a story about middle-level gangsters seem like the Fall of Man. Similarly, the Aria from Bach's Goldberg Variations is very beautiful, but seeing Anthony Hopkins stroll around his cage to it in The Silence of the Lambs doesn't tell us anything about him that we didn't already know.

Film music by its nature needs to serve the film, not the other way around – which, incidentally, is why Disney's Fantasia is so horribly misconceived. If you love classical music, you sometimes have to accept that a filmmaker might take a beloved work and use it so well that you'll never be able to hear it the same way again. Stanley Kubrick did this so often that we haven't bothered to include him: if you can listen to Also Sprach Zarathustra without thinking of monkeys, or The Blue Danube without thinking of zero gravity, well, lucky you.

Here are six occasions when classical music is used brilliantly to serve a story:

1. 'Ride of the Valkyries' from Wagner's Die Walküre – Apocalypse Now

We couldn't leave it out, could we? Apart from the Bridal Chorus from Lohengrin ('Here comes the bride'), this is the only bit of Wagner that nearly everyone knows, and it's thanks in part to Coppola's recognition of the not-so-latent aggression in Wagner's music. Nothing makes an air attack on a poorly defended native village seem heroic like a bit of swooping Teutonic romanticism.

2. 'Allegretto' from Beethoven's Symphony No 7 – The King's Speech

The second movement of Beethoven's Symphony No 7 builds slowly but inexorably from near silence to epic grandeur, and it was an inspired choice for this scene, in which Colin Firth's George VI, speaking on radio, must somehow inspire hope in the nation without coming across like the desperately insecure and unconfident woobie that he actually is.

3. The Flower Duet from Delibes' Lakmé – The Hunger (NSFW)

Catherine Deneuve, Susan Sarandon, a wine stain on a white jumper, a lot of gauze, and a soundtrack by Delibes. It took a few centuries for classical music to become authentically sexy, but when it did, the French in particular took it and ran with it. If you prefer your love scenes less vampire-y, consider the similar but warmer use of Debussy's Clair de lune in Garry Marshall's Frankie and Johnny (where, to be fair, it was taken from Terrence McNally's original play.)

4. Toccata in Fugue in D Minor BWV 565 by Bach – Rollerball (1975)

Norman Jewison's 1975 original is one of those gritty 70s dystopian classics, in which sporting star Jonathan H (James Caan) learns just how corrupt and evil is the world that his sport distracts people from. (The first part of The Hunger Games trilogy is basically 'Rollerball with teenagers'.) As Jonathan lays bare the ugliness of the spectacle to the crowd, and they rally behind his name, Bach's flashiest organ work suddenly sounds like the fanfare to a revolution.

5. Overture to Mozart's The Marriage of Figaro arr. Elmer Bernstein – Trading Places

The opening titles of John Landis' Ackroyd/Murphy vehicle show dozens of anonymous Phildelphians going about their business, unpacking vegetables, butchering meat, laying out fish: these are the very commodities that the film's characters deal in, and Elmer Bernstein's tidy arrangement of the Overture from Mozart's Marriage of Figaro gives an otherwise mundane montage a sense of order and a thrill of anticipation. It also works on another level: The Marriage of Figaro, like Trading Places, is in part about a wronged servant foiling the schemes of his rich master.

6. Adagio from Schubert's Sextet in C Major – Conspiracy

This quietly chilling 2001 BBC/HBO TV movie is a dramatisation of the 1942 Wannsee Conference, at which a group of prominent Nazis convened in a Berlin villa and formally sealed the fate of Europe's Jews by agreeing to leave them to the mercy of the SS. Towards the end, Kenneth Branagh's affable but amoral Reinhard Heydrich finds a recording of Schubert's Sextet and cheerfully observes to sidekick Adolf Eichmann (Stanley Tucci) 'The adagio will tear your heart out.' Later still, Eichmann puts it on, in the scene you see here. The music goes on to play over the film's closing titles, evoking all the empathy, compassion and humanity that's been absent for the entire movie – and incidentally showing up how it's quite possible to love great music and still be a complete scumbag.