How do producers like Obscurest Vinyl use AI to make realistic fake recordings?

Hello,

First, I want to apologise for taking offence when asked to upload a score so QA volunteers could look at it instead of just "putting in a ticket". In the end, I found such a minor issue that I don't think I should have brought it up in the first place.

You may have heard dirty songs by a man publishing as "Obscurest Vinyl":

https://www.youtube.com/watch?v=L_DyhWl30V4
https://www.youtube.com/watch?v=7zTei5RMhQ8

I don't know how exactly he did this, and I want to ask the Muse Score community if you have any thoughts. I would love to see public domain software and synthesised samples used to make stuff like this.