This rotation I am labeling ostinato in 2nd grade. At the end of our lesson, I have had my kids count the ostinati while watching the video. After watching we discuss how many we heard. They love this and are still talking about it.
If you are going to show this video to your kids, I would stop it just past a minute. I usually stop it when Harry and Snape argue back and forth. If you're anything like me, you're wary about the word "bomb".
Have you come across any other good examples of ostinato on YouTube?