"PowerPoint just accepts mp3 and WAV music files." Not quite true. If you
press the down arrow on the insert sound from file option, you will see that
you have at least 18 different file type options to choose from.
--
Michael Koerner
MS MVP - PowerPoint
PowerPoint just accepts mp3and WAV music files. So make sure you have
taken the right sound format during the first step.Then you can add
some music file to your presentation and set up the effect of your
presentation too.
If you have PowerPoint 2007:
1>insert the music file:
go to insert >sound>Select Sound from File ...choose the sound which
you want ,Click OK and a message prompts, saying How do you want the
sound to start in the slide show? Click Automatically.
2>Set up the effect of the sound:
1. click animations tab, then click the custom animation, you can see
a pop-up window.
2. Click the sound file that you want to set, Click the drop down
arrow of the music item you just added from the Custom Animation list
and select Effect Options.
3. A window named Play Sound displays. Select After and then set the
total number of slides .Now when you select OK and exit the custom
animation box, your sound will continue to play.
http://www.ppt-to-dvd.com/learningcenter/how-to-add-music-song-to-powerpoint-presentations.html