If you would like to add some music to your slideshow presentation, PowerPoint 2013 gives you three options. You can add your own music files from your computer, select music clips from Office.com, or record music yourself using your computer’s microphone. Once the music is added, select how it should play using the customization options provided.
Launch PowerPoint and create a new or existing presentation file. Click the "Insert" tab, then select "Audio" from the Media group.
Click the "Style" icon to have the music play automatically in the background when the slide opens, or select "No Style" to have the music play only when its icon is clicked.
Click the sound clip in the Animation Pane and then click the "Arrow" that appears beside it. Many of these options relate to syncing the music with other animation effects. For example, if you have additional animation on the same slide, such as a video or effect, you can select to start the music either with that animation or after it. Click either "Effect Options" or "Timing" to open the Play Audio window.