Music can help set the mood in your presentation
Dave Paradi's PowerPoint Blog
JANUARY 15, 2010
You can search for royalty free music that allows you to play the music without paying a royalty each time you use it. If you want to use a popular song, make sure you have the proper license from one of the licensing organizations such as ASCAP or BMI in the U.S. You can use a free audio editor such as Audacity to cut out the section you want and save it as an MP3 or WAV file that can easily be incorporated into your PowerPoint presentation.