In the old days, it wasn’t uncommon to put an AM radio near a computer or a monitor and deliberately cause interference to have a crude form of sound generation. Did you miss out on that? No! Thanks to [luambfb] you can now do the same trick with a common LCD monitor. You’ll need the horizontal refresh rate of the monitor in question.
Of course, doing it is somewhat less interesting than learning how it works. The effect relies on the fact that the LCDs emit signals as it refreshes a row. A black row emits relatively low energy while a white row emits more. Grayscale… well, you get the idea.
The software takes an input file that allows you to compose your own tunes. There is a fixed number of beats per minute and a set of notes and rests encoded in a text file. The project borrowed ideas from an older project known as Tempest for Eliza which you can see in the video below (there’s also a video of this project over on its page).
Tempest, of course, comes from the term for reading the data on a monitor using these signals which is possible, but difficult. While it might seem this is a modern issue, its origins date back to WWII.