When you open the program, go to the "Manage" tab. Click on your show & go to "edit". In the edit area, go to the "Playback" tab. You should see an area on the left that show the song that the program "chose" for you. Go to the dropdown menu & select "Custom". There you can add your own MP3. You'll not be able to use your custom music on the Roxio site due to copyright laws, however. If you put the show on your personal website, then you can use your own music. If you want to see what I did on my site, go to www.theweddingmeister.com & click on the Photography page. I'm VERY proud of what I was able to do with PhotoShow 5.
You are welcome to email or PM me if you get confused.