Fire Organ

Created by Nathan Stodola for his mechanical engineering senior project at Union College, the fire organ is a musical instrument that uses the laws of thermoacoustics to create the oscillations in the air we hear as sound. Like traditional organs, the pyrophone ("flame sound") has one pipe for each playable note, activated by a piano keyboard.

However, the sound in this instrument is produced by a temperature difference imposed across a stack of closely packed channels.
The hot temperature is maintained by propane flames and the other end of the stack is kept cold by running liquid nitrogen through a heat exchanger.

Boasting a range of 14 notes, the organ is one of the only instruments in existence that uses heat to create a tone.