Also highly recommend that you find some good music for presentations and use it as background noise. When choosing the tune for your presentation, be sure to choose something fairly soft and simple. The last thing you want to do is distract people from the actual presentation by a attention-catching song. Music loops for presentations should be simple, uninteresting, and quiet andin other words, it should be nice background music.
Another route is to not choose music per say, but rather, sound effects. For instance, you could have a specific sound when the slide changes, or when a bullet point is displayed. If you choose to do this instead of using regular presentation music, then you will need some sort of music production/editing program.