First 4 and a half minutes.
The music in the first scene is very up beat and fast to match the chasing happening, whereas, in the police scene the music is just a few high note being played to build tension and suspense. Once the scene has changed back to the chase, the tempo builds up again and there are a few stabs which indicates to the audience that something bad is about to happen. There are a lot of different instruments being played at once and although they are organised, they feel chaotic, which may be what the guy who is being chased feels like - so he doesn't know what to do or where to go and is panicking. When the two men become face to face the amount of instruments being played goes down but it is still fast which means the audience can still feel the tension, even though they have stopped running. Just before they run at each other, a note crescendos and this tells the audience that something is about to happen. The next sounds are mainly diegetic, as its the noise of one of the characters falling through the bridge/pathway and after that the music is like what it was in the police scene, just a few high notes being played and this is, again, to build and keep the tension up. This music continuous onto the next scene with the police, where the music is joined but the sound of police radios to show that they scene has changed and they are at a different location. Again, when the radios stop, it is an indication that we are in a different location. In this scene, the only other sound is diegetic which is them shouting and one man slamming his food down repeatedly - this is done to make the audience jump and keep them interested.
When the scene changes to the police - with the use of the radios to hear this, as they used a sound bridge - and after Luther tells them where the girl is, the music changes back to up tempo and lots of different instruments start to play, again this may be parallel to what the police are feeling, as they are trying to get the girl out alive. The sound bridges over the next few scenes. On one bit where Luther is saying about lying, they've cut it so that it makes the audience feel afraid of him and it makes him seem powerful.
As soon as they find the girl in the box, the music changes back to the few high notes to keep suspense and it doesn't give any clues as to whether the girl will make it or not. More stabs are heard here, again to keep the tension.
Once the girl start breathing the music turns to something more happy and this reflects not only the characters feelings but also maybe the audiences feelings too. However, it then turns to something more sour as you can here the shouts of the man that is hanging on for dear life and this gives the audience the feeling that Luther is about to decide whether to save him or not. Now, instead of the high pitched notes, its turned to just a few low pitched notes, being played at length. This matches the feelings of the detective as he lays off the names of the children that this man has apparently murdered. They have used the different volumes of his voice to make the audience jump and to try and understand what the character is feeling.
The music very gradually gets louder as the man begs for his life and then, like before, a note crescendos building up the tension and making the audience wonder what is about to happen. Then as his hands let go of the bridge the music stops and this is to make the audience feel the full effect of what has just happened. The music starts again after the noise of him crashing to the floor and it is the same low notes as before and they add in - what sound like out of tune notes - so it matches the characters mixed feeling about what he had just done.
This sequence uses a lot of sound bridges and parallel sounds to keep the tension up.