There are certain limitations when you don't have the option to place storyboard elements underneath a video. In the case for storyboarding the background in a song with video in it. Playing without the video will be a black screen.
Also if you still wanted to have storyboarded backgrounds for people who prefer to play without the video, this wouldn't be possible either.
Also if you still wanted to have storyboarded backgrounds for people who prefer to play without the video, this wouldn't be possible either.