So I'm figuring you want background music, first you gotta goto Magos model editor and find the WC3 MPQ and look in the sound section. I already did it for you so here's the path to the sound and how to do it
First you want to goto your import manager, not your sound manager.
Import the sound you want, though I suggest first making the sound as short as possible and reducing the size of the sound as much as you can, there are for sure tutorials on how to do that, since it's not limited to just sound files that need to be squished
Then click on the path
Then change the path into the main Human background music which is
*Sound\Music\mp3Music\HumanX1.mp3*
Then to make sure that everyone gets this sound, goto player properties and make everyone a human or whatever race you wish for them to be, you gotta look up your own for the other background music though
And viola, there you go, a non trigger music