Would you like some music to play before your PowerPoint ‘show’ begins? Most people do this by playing music separately from PowerPoint then clumsily switching over when they start speaking. There’s a better way.
The more elegant method is adding repeating music to an opening slide.
Add the audio file then change these options on the ribbon at Playback | Audio Options.
Loop until stopped.
Simple as that.
Do the same on the last slide for the ‘play out’ music that can continue until you shut down the presentation.