 This here is a Koenig sound analyzer made by Rudolf Koenig in the 1880s in Paris. What's so amazing about this machine is that it allowed scientists for the first time to do something they couldn't do before, which was make something invisible, sound waves, visible, so that you could actually study sound as it happened in real time using your eyes as well as your ears. As you rotate this mirror, the flames start to appear as a single line or single streak across the mirror, and depending on which resonator is resonating at that time, which harmonics are in the sound, those particular flames will start to jump and dance on the mirror, and that tells you which one of those resonators, which one of those harmonics is actually being activated by that particular sound. So artists would then draw those sounds out and draw what was appearing on the mirror, and that was their record, so they could start to study the different harmonics that appear in different sounds. Ready? Oh, we got it, see? The G. You see, organ pipes are really rich in harmonics, that's why the whole thing is lighting up. This is the best one ever, I've tried.