Background Audio Cool Trick
Just wanted to share a way to add audio across all slides in Storyline 2 There are a few posts on here about this, and I found this method to be super simple.
**Please note that this is just a cool trick, and not a built in feature of Storyline 2.
Publish your course, open the story.html file with Notepad, scroll to the bottom and add this code
<audio src="YOURAUDIOHERE.mp3" preload="auto" autoplay loop></audio> with a space before the </body> and place your audio file into the published output folder and there you go. That is it.
Here is an example, http://bit.ly/1sy5dkV and the output folder is attached.