[BradJudy]

Do any of the classes involved in this project have a Rubens Tube?  http://en.wikipedia.org/wiki/Rubens'_Tube

It was one of my favorite items from my high school physics class and is a great illustration of sound waves and waves in general (although it can confuse people on the longitudinal vs transverse nature of sound waves). 

[S Clark]

I have seen these for years in catalogs, but have never had one.  Can't say about the other schools.

[BradJudy]

They are pretty neat and simple to build if you have some moderate tools/skills.  Basically a steel pipe with holes drilled in it, capped at one end, speaker at the other and an inlet for natural gas.  I'm pretty sure our physics teacher built ours. 

I've never looked in a catalog for one, so I'm not sure how the commercial ones are made.