Does the shape of the container matter when constructing an acoustic standing wave? Is there an advantage of using a cylindrical container over a rectangular prism?
The shape effect on fundamental pitch is slight, but the effect on the overtone series is significant. Most wind instruments have cylindrical shapes for this reason, and also because square cross-section pipes with bends in them are more difficult to fabricate. This is a topic about which a lot has been written in the field of musical instrument acoustics/physics of musical instruments- far too much to cover here.