How to play a sound throughout a map?

[jdagenet]

How would I go about playing a sound at it's full volume thoughout the entire map? I can't seem to figure this out though I'm sure it's easy. I put this in my SNDINFO lump:

world/expload/first  EXPL1

And then in ACS I tried to use the "thing_sound" function and play the sound at a thing but, when I go to test it, their is nothing. I'm constantly looking through the ZDoom Wiki for solutions but I can't seem to find any, or perhaps I'm over looking them. Could someone please come up with a solution that could help me out?

[EarthQuake]

AmbientSound is probably what you want. It will play the sound at the specified volume and is heard by all players. The other is LocalAmbientSound and works the same way, except only the activator will hear the sound.

Script 1 (void)
{
  AmbientSound("world/expload/first", 127);
}