I have a friend who works for a defense contractor and those guys get shipped some pretty weird stuff.  The various cardboard containers used to ship this stuff tend to be sturdier and more interesting than the normal, everyday run-of-the-mill cardboard.  A good example of this is the heavy yellow cardboard tubing that makes up part of the frame of the Mailing Tube Marimba.  But then again, just like the rest of us, big time defense contractors also use standard mailing tubes and corrugated boxes.  So my friend gave me what amounted to a room full of cardboard "Tinker Toys" -- from which grew three very different sound sculptures.

The Mailing Tube Marimba is a fairly simple design.  Mailing tubes were cut to various lengths (for pitch), spin painted individually (using variable speed drill) and then fit down into legs made of... you guessed it... more cardboard tubing.  The entire piece is modular and packs up into an empty vacuum cleaner box.  The sound produced by the tubes depends upon the type of beaters used to strike the plastic tube tops.  "Super balls" on chopsticks give a warm, round tone, while wooden balls on chopsticks give a sharp, hardwood sound.