A personal favorite of mine is 10 hours of procedurally generated Djent [0], a style of progressive heavy metal. It makes excellent background music.
As an anecdote, I've used several of these white-noise-black-screen videos as a sleep aid while I needed my phone's screen "off" and I didn't have other options.
The music is the generated part. The video is visualizations on the music. The channel author describes the process [0], but the whole channel is worth checking out.
As an anecdote, I've used several of these white-noise-black-screen videos as a sleep aid while I needed my phone's screen "off" and I didn't have other options.
[0]: https://www.youtube.com/watch?v=52SRWJ2pMXI