Sorry if this has already been pointed out but Bernard Hermann stole/used the theme from Wagner's "Tristan and Isolde" but I don't remember seeing Wagner's name in the credits of Vertigo. It is also used in Lars von Trier's  "Melancholia".

What the Silence is in my view… A mind-blowingly great metaphor. They are the manifestation of our own ugly animal natures. They are the physical manifestation of man's nature - a monster in a suit. We are driven by terrible self-interested forces which we are in denial about - our true, terrifying primal selfishness.…

Don't miss the significance of the date when time stopped - 22nd April 2011, which was Good Friday. Moffat's allegorical boldness is thrilling in the Christmas specials and season finales. He even cheekily dressed the Doctor as Jesus in front of a Roman Emperor in this one -  which was a wonderfully brazen touch.  I…