This sondtract indeed introduced the whole story. Yeah, It's Hans Zimmer's traditional style, comparing with strange Sherlock Holmes.
No doubt that the last song "Time" should be the main title in this album is absolutely perfect. Time is elapsing, everyone getting older than before. Regret in mind, in memory, this one cannot be forgetful, on contrary become deep and painful.As said in this film, "The moment’s passed. Whatever I do I can’t change this moment. I’m about to call out to them. They run away. If I’m ever going to see their faces I’ve gotta get back home. The real world." by Leonardo DiCaprio, this song express sadness to us, as time goes by.