There is a beautiful symmetry to the electrical principle commonly used to translate acoustic sound into an electrical signal and back into sound again. Likewise, any dynamic microphone (i.e., based on a coil and magnet design, such as the ubiquitous Shure SM58, spat upon by singers in clubs around the world) can be used as a low-level speaker or headphone. Microphones have very delicate coil windings, however, and can be easily blown out. A related experiment will introduce to the fundamental operating principle of what is generally accepted to be the first music synthesizer: the Telharmonium. Patented by Thaddeus Cahill in 1897, the Telharmonium weighed in at over 200 tons and resembled a power station on a railroad flatcar more than a musical instrument. Artist Lorin Edwin Parker has built an off-the-grid steam-powered synthesizer by connecting a direct current motor to a homemade steam engine.