Note: This technique was last tested using PowerPoint 2003–yes, this is a very old post!
Also, this seems to work in PowerPoint 2007 as well, but fails in PowerPoint 2010 and higher because the sound stops playing when you step into a custom show.
This technique assumes you know how to loop sound across slides in PowerPoint.
When you loop the presentation using the options in Slide Show | Set Up Show, you’ll find that the music starts again on the first slide whenever the presentation is looping. To overcome this problem, here is a solution:
- First of all make sure all your slides are set with automatic transition timings. If your first slide has a sound inserted and set to play across slides, remove the music clip. You can select the sound icon, and press the Delete key.
- Now place your cursor before the first slide in the Slides pane, or in Slide Sorter view. Then insert a new “kick-off” slide at the beginning of the presentation. This is the slide where you will start your music.
- Next, mark all slides from your second slide through the last slide to be a custom show. Do note that all these slides already have automated timings to advance slides. Make sure Slide 1 does not have automated timing to advance slide.
- Add a sound clip to the first slide, and set it to play across slides.
- Add an Action Button (or hyperlink) to the first “kick off” slide. Bring up the Action Settings dialog box, and not the Hyperlink dialof box, and link to your custom show. Slide 1 should now have two items; the sound file and an action button or hyperlink to start the custom show.
- Set up the slide show to loop until ESC using automated timings and showing all slides.
- Save it as a .PPS or .PPSX (recommended).
PowerPoint MVP Glenna Shaw helped with this answer.
Plus, there’s a sample file for this technique that you can download from Glenna’s site. The sample is called Loop Sounds.
When you run the slideshow, Slide 1 will start the music and you’ll need to click on the Action Object or Hyperlink to start the custom show. From that point on, the presentation should loop through Slide 2 to the Last Slide without resetting the music (unless you have some other sound stop it between Slide 2 and the Last Slide). If you saved it as a PowerPoint Show (PPS or PPSX), the whole thing will close neatly when you press Esc.