If you create lyrics videso than you should make template with lyrics. But I don’t see how it possible to adjust timing for different songs.
Main reason I think is because nothing happens. It is mostly still video for 2 minutes, shakes doesn’t count. Try to add some more dramatic look to it, add some more animated elements and check how things are for buyer looks like, how it is easy for him to customize things.
But the idea is really interesting, I hope someone can give more extended feedback. Good luck!