I can't believe no one has recreated the machine though. Perhaps someone will now.
Someone's HTML5 ... tribute? https://bits.ashleyblewer.com/portable-auroratone/?loclr=blo...
> [Stokes’] procedure was to cut a tape recorded melody into short segments and splice the resulting pieces into tape loops. The audio signal from the first loop was sent to a radio transmitter. The radio waves from the radio transmitter were confined to a tube and focused up through a glass slide on which he had placed a chemical mixture. The radio waves would interact with the solution and trigger the formation of the crystals. In this way each slide would develop a shape interpretive of the loop of music it had been exposed to. Each loop, in sequence, would be converted to a slide. Eventually a set of slides would be completed that was the natural interpretation of the complete musical melody.
I think this it:
How Brian Eno Created Ambient 1: Music for Airports https://reverbmachine.com/blog/deconstructing-brian-eno-musi...
It's kind of a kaleidoscope where the moving crystals are fused into a solid mass, creating a fixed slide.The energy for fusing the crystals can come from either big lamps (carbon arcs are suggested) or an RF heater. Plus there's an air compressor in there to blow air into the thing to cool the material and stir things up. Then there are two projectors, which take turns displaying two slides.
It belongs to the class of devices for which the technology didn't really exist yet to do it right, but somebody managed to kludge a prototype into working. See "Telharmonium"[1]