Are you looking for a good science connection in your music class? This blog (http://www.prekinders.com/2007/03/can-you-make-music-with-water/) has a great idea for an easy science connection! I think this would be great as you’re teaching your students recorder. It reinforces that the longer the column of air, the lower the pitch. It’s a great visual as long as you tell the students to focus on the air and not the the water. If they’re focusing on the water, it can be more confusing.
Have you shown your students something similar? Do you find it helps them understand?