This is an orignal song that I made myself called "Marching Forward" that I modded into the game. Although the song originally has vocals, I decided to use an instrumental version instead.

The looping might be a bit janky, and the stealth part might not sound the most "stealthy", but I intended for this to be used more in loud only heists anyways.

Here is the song in question (note: the version you hear in game doesn't have the vocals)
[https://youtu.be/1pFcewsyWpI]