This mod can be installed in either "mods" or in "mod_overrides", though this requires SuperBLT for this to work.
I've ported all of the music tracks from a match-3 marble popper game called "Luxor Evolved" into Payday 2 Heist Tracks and a Menu Tracks. What's cool is that in Luxor Evolved, the music gets even better the better you play. So I incorporated them into Payday 2, whereas the music gets better as the assault is imminent.
You're only installing one folder, which contains 7 heist tracks and 15 menu tracks.