You can add video or audio to a slide. When you show the slide during a presentation, by default the video or audio plays when you click. You can set video or audio looping and start timing to make the video or audio start automatically when the slide appears. You can also add a soundtrack that plays for the entire presentation.
Note: Video and audio files must be in a format that QuickTime supports on your Mac. If you can’t add or play a video or audio file, try using iMovie, QuickTime Player, or Compressor to convert the file to an MPEG-4 file (with a .m4a filename extension) for audio, or a QuickTime file (with a .mov filename extension) for video.
You can also record audio and add it to your presentation.
When you add video or audio file to a slide, the video or audio plays only when that slide is showing in your presentation.
Do one of the following:
Drag a media file from your computer to a media placeholder or to anywhere else on the slide.
Click 
in the toolbar, click Music or Movies, then drag a file to a media placeholder or to anywhere else on the slide.
To search for media, click the magnifying glass in the upper-right corner of the media window.
Select the video or audio on the slide.
In the Format 
sidebar, click the Movie or Audio tab.
Click Replace.
Select a video or audio file, then click Open.
A soundtrack begins playing when the presentation starts. If there are slides that already have video or audio, the soundtrack also plays on those slides.
A file added as a soundtrack always plays from its beginning.
Click 
in the toolbar, then click the Audio tab at the top of the sidebar on the right.
Click 
(to the right of the volume slider in the middle of the sidebar), then select one or more songs or playlists to add to the soundtrack.
To reorder the songs or playlists, select one, then drag it above or below another in the list. To delete one, select it, then press Return or Delete.
Click the soundtrack pop-up menu, then choose an option:
Off: The soundtrack doesn’t play.
Play Once: The soundtrack plays through the presentation and doesn’t repeat if the presentation is longer than the soundtrack.
Loop: The soundtrack repeats until the presentation ends.
If you want to play your presentation on a different computer or device from the one you used to create the presentation, choose Keynote > Preferences (from the Keynote menu at the top of your screen), click General at the top of the preferences window, then select “Copy audio and movies into document.” Doing so ensures the soundtrack is available whenever you play the presentation.
Some media files are protected under copyright law. Some downloaded media may be played only on the device where the download occurred. DRM (digital rights management) protected music can’t be added to the presentation soundtrack. Make sure the computer you’re using has permission to play all the media files included in your presentation.
You can set Keynote to optimize the format and quality of movies and images that you add to presentations.
To set video or audio looping, adjust playback volume, or make other edits to your media, see Edit video and audio.