zodiac trailer analysis(need to finish)

conventions
low key lighting is used many times often to hide characters faces or because of the setting they are in for example a basement or in the middle of the street at night this gives a effect of suspense and mystery because you dont know who the character is or what they will do so it keeps you guessing and adds to the suspense of the scene.

sound
gun shots in time with fireworks going off and then the beginning off the tension music as well. there is noises off telephones going off that arent in the scene depicted while they are looking at  the cipher which gives the effect of unknowing because they don`t know what the cipher says and are confused by it.A constant tapping noise in the background represents the constant threat of the killer but it wont go away just like they cant find the killer . then half way through the trailer the music completely changes and turns into a up beat soft rock song which changes the mood of the trailer and goes against what the first half did. there is a convention of heavy breathing in a phone call in one of the scenes , this is goes back to the same mood as the first half of the trailer but has more effect because it is between a up beat music .There is a point where the music turns off and it is in a dark basement and there is a creaking off floorboards and a humming are the only two sounds that can be heard but the characters face can be seen and he looks very scared and surprised to hear the sounds and after that another character standing half in the shadows turns a light off as a crash sound happens and then changes scene.