In order to hear the music properly, you will need the custom WWise files I generated for the map.

Only CLIENTS, servers are not required to do this! All audio is streamed locally.
You can grab them from the forums because I can't post DL links here apparently:
[Mediafire & MEGA]
https://forums.tripwireinteractive.com/forum/killing-floor-2/killing-floor-2-modifications/level-design-ac/beta-map-releases-aa/2292038-kf-dd-towersiege

Go to your Killing Floor 2 directory, then go to KFGame\BrewdPC\WwiseAudio\Windows and drop ALL the files in there.

Example Dir: E:\Games\SteamLibrary\steamapps\common\killingfloo r2\KFGame\BrewedPC\WwiseAudio\Windows

Once you extracted them into the Windows folder in WwiseAudio, you're set! Boot the game and hear that Dungeon Defenders music/audio!

(I might do a tutorial on how to do custom Audio in maps in the future. It would seem to be a thing that most people would like to have custom music in their map.)

-Custom Audio FAQs/Known Bugs-

• KF2 ingame music starts playing after unpausing the game in singleplayer!
  --Answer: Press your 'Flash Light' button to clear the ingame music. (I had to do this due to no access to TWI's Wwise Back end).
  
• My custom audio overlaps trader wave and or combat wave on a rare occasion
  --Answer: This is a known bug I've noticed that happens very rarely, it's due to the Unreal Kismet not executing that certain WWise event causing it to just be at a "broken" state. Currently looking for alternatives to fix this.