Open a presentation, then do one of the following:
Drag a media file from your computer to a media placeholder or anywhere else on the slide.
To add a video, click on your Mac.
Open a presentation with video or audio, then click the video or audio on the slide to select it.
In the Format Add a video description.
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.
Go to the Keynote app , then select one or more songs or playlists to add to the soundtrack.
To reorder the songs or playlists, drag them above or below another in the list. To delete one, select it, then press Delete.