How can I insert a .mp3 file in the whole presentation?

[Luiser]

I want to play a .mp3 file during all the presentation. It should start
automatically with the first page an last until the end of the presentation,
without pauses nor re-starts.

Thanks

 

[John Wilson]

Have a look here http://www.pptalchemy.co.uk/keep_playing.html

 

[Michael Koerner]

This is a good place to start
Play sounds across multiple slides (A WAV runs through it)
http://www.pptfaq.com/FAQ00047.htm