Implementing music in L4D2 maps?

So I have been trying to implement music in my maps, such as the campaign intro or the Safe Rooms. The thing is I can’t manage to get it to work properly, some help would be greatly appreciated.

you can use a ambient_generic and set it to play everywhere. then set the music. and have it triggered when you do something.

I have already tried that, however the second trigger, which I use to fire an FadeOut output, and is supposed to stop the music, sends this error into the console:

!! ERROR: bad input/output link:
!! ambient_generic(music,FadeOut) doesn’t match type from trigger_once()

Jezz just use the stop playing command :V and when it plays once It’s should stop.

That stops it immediately and sounds very unprofessional.

Alvaol - the fade I/O is broken. You will have to find another method, Sorry.

Yeah, have the audio itself fade out.