Ok makes sense. And yea I think you'd have to be in an inspired state and work quickly. I can't imagine how long it would take with a slow/perfectionist approach. You nailed it. I love the different genres this goes through. Btw this is the first time i've heard something like this here, but it's only about 15mins:
project
Actually, I just wanted to keep the time similar to the original track. I came up with the idea to use the vocals as some sort of ambience and so I made the mix. But there was a lot of other ambience left over, so I just continued making more stuff ;)