Post Production: Non diegetic sound

Thriller films tend to use music that elevates the tension created by the visuals and I've been in search of something similar. I researched on different websites (soundcloud, sound bible, freesound, youtube) for a music that would fit with the scenes. I finally found a music on Youtube which starts off slow and then builds up. It does not build up too much either which is great because I don't want the music to overpower the voiceover.

Here's the link to the music: https://www.youtube.com/watch?v=hoqMpJC0tZY&index=1&list=LLyUjpS3EK8Sju3DOtYhvHWg

This music is free to use as it says in the description.

The music does get very high towards the end so I trimmed it before it does so. I trimmed small sections of the song to create a loop at the very end so the tempo remains the same. Towards the end of the sequence I lowered the volume of the music and added the cinematic boom sound effect (downloaded from youtube) at the plot twist. I lowered the volume of the music so it does not stop abruptly but plays smoothly as if it's all part of the same music.