I saw "The Dark Knight" at the movies back then. An extremely dark Batman movie with the now legendary portrayal of the Joker by Heath Ledger. He embodies absolute evil and presents Batman with extreme challenges. Heath Ledger was posthumously awarded the Oscar for Best Supporting Actor for the role. He died of an overdose of medication shortly after filming.
The soundtrack by Hans Zimmer and James Newton Howard weaves a tapestry of sound that runs permanently behind the action, typical of Hans Zimmer. The gloom is underscored by extremely deep bass in several sequences. Why so serious begins with one of the Joker's three themes. Swiss cellist Martin Tillmann raises the pitch of one of the cello's strings higher and higher. The viewer now knows that something is wrong. This is followed by the two other themes of the Joker. A nervous string theme and an electric guitar and percussion theme. The sound goes deep down at min. 3:28 and from 6:14.
Hans Zimmer was born in Frankfurt am Main in 1957. He is a legend today. Whether Gladiator, Batman, Pirates of the Carribean, Interstellar or Interception. He made the soundtracks for all these blockbusters and for many more films.
Regarding the Batman trilogy, he says that it looks like a movie, but there are 12 years between the first and third parts. Regarding the Batman music, he says that sometimes you get the feeling that the images and music fit together perfectly. That was the case here.
For all those who have never heard of Hans Zimmer, you can listen to his life story here.