mp3 file won't play in Keynote

Hello R8Evans,

Thank you for reaching out to Apple Support Communities, and we'll be happy to help in any way we can. We understand you're having issues with playing audio in Keynote. Try the steps listed here to see if they resolve the issue: Play a movie or audio across slides in Keynote on iPhone, iPad, or Mac

"To play a movie or audio across slides, add the same file to consecutive slides. You can then adjust settings for the file to change how the movie or audio looks and sounds from one slide to the next.

For example, you can set the volume of the file on each slide independently, or have a movie change position on the slide while still playing through. Animation steps for other objects on the slide like Build In, Action, and Build Out continue to function while a movie plays.

Add a movie or audio file to slides

To play movie or audio across slides, add the file to consecutive slides in your presentation.

Add a movie or audio file to a slide on iPhone or iPad

1. Select the slide that you want the movie or audio file to start playing from.
2. Depending on what you see in the toolbar, tap the Insert button  then tap the Media button , or just tap the Media button .
3. Add the file to the slide:

• To add a movie from your photo library, tap Photo or Video, locate the file, then tap it.
• To add a movie or an audio file located in iCloud Drive or another location, tap “Insert from,” locate the file, select it, then tap Open.

1. Place the file where you want it to appear on the slide and resize it as necessary.
2. Add the file to each consecutive slide that you want the movie or audio to play across.
3. On each slide, tap the movie or audio file to select it, tap the Format button , tap Movie, then turn on Play Across Slides.
4. Turn off Play Across Slides for the last slide that you want to play the file across.

When you turn on Play Across Slides on a slide, the movie or audio will play across the next slide, even if you turned the setting off on the next slide. For example, if you want to play a movie across five slides but don't want it to play over the sixth slide, make sure to turn on Play Across Slides on the first four slides. Then turn the setting off on the fifth slide. The movie will play across the fifth slide and will stop when you advance to the sixth slide.

Add a movie or audio file to a slide on Mac

Use movies and audio files that are in a format that QuickTime supports on your Mac. If you can’t add or play a movie or audio file, try using iMovie, QuickTime Player, or Compressor to convert the file to an MPEG-4 file (with an .m4a extension) for audio, or a QuickTime file (with a .mov extension) for a movie.

1. Add the file to the slide that you want the file to start playing from:

• To add a file from your photo library or a song from your music library, click the Media button in the toolbar, click Movies or Music, then drag the file onto the slide.
• To add a file from iCloud Drive or another location, click Choose, locate the file, then click Insert.

1. Add the file to each consecutive slide you want the movie or audio to play across.
2. On each slide, click the file to select it, click the Format button, click Movie, then turn on “Play movie (audio) across slides.” 
3. Turn off “Play movie (audio) across slides” for the last slide you want to play the file across.

When you turn on “Play movie (audio) across slides” on a slide, the movie or audio will play across the next slide, even if you turned the setting off on the next slide. For example, if you want to play a movie across five slides but don't want it to play over the sixth slide, make sure to turn “Play movie across slides” on the first four slides. Then, turn the setting off on the fifth slide. The movie will play across the fifth slide and will stop when you advance to the sixth slide.

Use slide layouts

You can also add movie or audio files to a slide layout, then apply that slide layout to other slides. Movie or audio files will play across any consecutive slides that use the same slide layout. This way, you can create motion backgrounds, and guarantee seamless playback and perfect alignment from slide to slide.

Adjust the volume of the movie or audio file for each slide

You can set the volume of a movie or audio file on each slide independently on Mac, or an audio file on iPhone or iPad. For example, you might want to lower the volume on a slide you're speaking over, then raise it for a slide where you're not speaking.

Adjust the volume of an audio file on iPhone or iPad

1. On the slide you want to adjust, tap the audio file.
2. Tap the Format button , tap Audio, then drag the Volume control.

Adjust the volume of a movie or audio file on Mac

1. Select the movie or audio file on the slide, click the Format button , then click Movie or Audio.
2. Drag the Volume control.

Adjust other settings and use transitions when playing movie across slides

You can adjust the position, size, and rotation of the movie from one slide to the next. And, if you're using other transitions, the movie will continue to play on both the outgoing and incoming instances of the transition.

Some animations create interesting effects when playing a movie across slides. When you use Magic Move as a transition animation, the movie continues to play and expands to fill the entire slide as the presentation progresses from the one slide to the next.

If your movie or audio won't play across slides, make sure certain settings match on each slide.

Play across slides when you have long presenter notes

Playing a movie across slides can be useful when you have long presenter notes that won't fit in the Presenter Display. By duplicating a slide with a movie several times and splitting the presenter notes across these slides, you can click to show the next segment of notes while the movie continues to play seamlessly, no matter what transition is used.

If your movie or audio won't play across slides

If your movie won't play across slides, check these settings for each slide you want the file to play across:

• The Repeat setting (None, Loop, and Loop Back and Forth) for the movie must be the same on each slide.
• The trim setting must be the same on each slide (Mac only).
• If you have a build out on one slide and a build in on the next slide, the movie won't play across slides."

We hope this helps.

Cheers!

Why are you using a placeholder for a sound file? Placeholders do not work with sound files.

Instead, position the sound file on the slide by drag and drop the file onto the slide from a finder window.