Comparing sound in thriller openings

Today, in our media studies lesson, our group anylised the sound use in three thrillers: Day of the Jackal (1973), 1 hour photo and Se7en. I noticed that the sound used in all the thrillers are not particularly different, but some of the techniques slightly vary.
In 'Day of the Jackal', there is non-diagetic music at the beginning, which is upbeat, so you may not be able to tell straight away that this is a thriller. However, further on during the opening sequence, as soon as the title is displayed, the music becomes slower and more eerie, creating a mood of suspense.
'1 hour photo' differs from this in terms of sound use. Instead of the music changing, there is eerie music, which plays throughout the opening sequence and maintains the same simple beat, which is a way of building up suspense. I also noticed that silence can be very effective to use in thriller movies as there was a part where a shot of a camera was shown in a still shot and no sound was made for several seconds and was building up suspense because we didn't know what was going to happen next.
'Se7en' uses a completely different technique compared to 'Day of the Jackal' and '1 hour photo'. The sound starts off diagetic, when a metranome is ticking. This method is used to hypnotise the audience. The sound later seems to be the sound of many items being used at once, and non-diagetic. It is only later on during the opening sequence of 'Se7en' that rhythmic eerie music is played. The music has, for example, scraping noises and saw noises, which give it more of a thriller feel.