I've been taught how to before but i've totally forgot. How do i do it?

In powerpoint 03:
1. click on the insert menu
2. Find "movies and sounds"
3. Click "sound from file"
4. select your music file.
5. Select how you want it to play (auto or when clicked)
6. To choose more advanced features, right click on the sound icon on the current show.....choose "edit sound object"
or
choose "Custom animation"...find the file shown on the right...right click on the file....choose "effect options"

hope that helps!