I would like to see the persimmon tree.

The same people who worked on the soundtracks for other games in the series also worked on this one. I have no idea why you think it was made "on the fly."

Paul Romero himself wrote about this. He had to use loops, remixing the same moments, and so on. In short, it was a shoddy job, and he was surprised when the game was praised for its soundtrack. Apparently, there wasn't enough time to create a full-fledged soundtrack.