I ask about a Zoom Tube @ every indy Toy Store I come across. A young woman in a Lawrence toy shop actually had seen one as kid.
~ 1985, we gave a Zoom Tube as a XMAS gift to my wife's nephew's 5YO son. He has no recollection (I'm guessing his dad confiscated it ASAP.
Imagine a cardboard shipping tube, ~ 3" in diameter & 3' long. Wrapped in some psychedelic paper. Inside I hypothesize there was a metal spring, free on one end to vibrate. As soon as you move the tube, the spring vibrates a wavelengh of sound which travels the length of the tube & reflects back to the point of origin. This goes on for an eternity, until some adult latches onto the tube & holds it still (likely for an eternity).
IF I'm asked to describe the sound, I say that it's like the time your Uncle Ed got on top of the chickenhouse with a sledgehammer & did a rhythmic beat on the tin roof while you were inside.
We got the original Zoom Tube at a gift shop in some science museum. I strongly believe it was the product of an inventor who also marketed them & was never picked up by a mainstream toy co. Google has been of no help in my exhaustive searches. I'm guessing the inventor has passed away. Patent? I don't know.
Here's another one for audiophiles:
Take a lo pipe. Drill holes at X mm intervals. Attach a speaker to one end; a lab gas jet to the other. Hook your speaker up to an amp (should be one tonyb would term "musical") & play a full-spectrum song (Also sprach Zarathustra comes to mind, with those initial 20Hz frequencies). The gas in the pipe is forced out the small apertures, & once lit forms a blue flame graphic wave rising above the pipe in correlation with the frequencies & amplitudes of the music.
The Google examples so far don't do justice to what I've observed. Flames are mostly yellow (insufficient air for complete combustion), rather than blue.
Here's a more scientific video. I suggest having Calculus before viewing; ~ 4'45" is the best part IMHO:
NOTE: I've never had kids. I assume no liability for irresponsible parents. I once showed my 8th graders an electric chair for a large dill pickle, speared on nails at each end. You then plug the chair into 120V. What do you suppose the pickle does in your darkened classroom? Why does it eventually NOT do that any longer? The first correct response came from a mainstreamed special ed student; and he named the correct element.
The next day, 2 mainstreamed students came to class, excited to tell me that the electric chair also makes toast, IF you unplug it fast enough (BIG SMILES ON FACES).