An oscilloscope can be made to display shapes by playing sounds into it. Making music from these sounds while simultaneously drawing images with those sounds takes things to another level.
In the video I fix up and put an old oscilloscope to a new use, and show how you can watch these audio-visual demos even if you don't have a oscilloscope by using a computer.
If you want to skip the preamble and repair section and jump straight to the demo - it starts at 05:00
Jerobeam Fenderson’s Oscilloscope Music
Jerobeam Fenderson’s Youtube Page
If you have any technical queries - the FAQs here should answer them
Oscilloscope Emulator for Windows, Mac & Linux
Reddit Oscilloscope Music Page
Here’s a link to a Free Oscilloscope Demo called Youscope
If you like seeing oscilloscopes put to unconventional uses - perhaps you'll be interested to see Quake played on one. https://youtu.be/GIdiHh6mW58
You may also be interested to know that the 'first video game' "Tennis for Two" was played on a scope display in 1958
If you have an old X/Y capable oscilloscope you'll probably need a pair of BNC male to RCA female converters like these http://amzn.to/2f67Qsk if you want to connect audio devices to it.