The principle of resonance is all around us -- it enables electronic communication but it also causes mechanical structures to fail (remember the Tacoma Narrows Bridge collapse). The ME-311 Resonance Demonstrator provides a clear, easy-to-see demonstration of resonance. The device consists of a horizontal rod to which are affixed three pairs of spring-steel wires. A mass is affixed to the end of each wire. When any wire is "plucked," its equal-length counterpart of the opposite side of the device oscillates with large excursions while the other four wires and weights remain relatively motionless.