Music during the game?

is there a way to have a song playing while the game is going on? like an mp3.

Huh? There usually is a music theme playing that is an mp3. You can import your own mp3 into a map and have that play if you want.

Basicly what Nemesis said, you import it and then you can play it by using a trigger action "Play Music", be careful though, most mp3s are 3 mb in size, and wc3 maps rarely go over 1 mb. You might want to use TotalRecorder or something to compress the mp3 so it takes less space, at the expense of music quality.