More on the stem separator: at least for the default models, it seems to assume that instruments will be present. If your song has guitars, bass, drums, piano, and vocals, it'll do fine. I threw a song at it that had vocals, several horns, drums, and an organ-style keyboard, and it didn't get those at all. I imagine I'd have to choose models meant for such instruments, but there are a LOT of models, and they don't always have helpful names.

@alexhall I know Gianluca the guy who put this together. Can ask him to add an info button that summarizes the strengths of each model.

@Scott That would be cool, thanks. Other than that, it's dead simple and does exactly what it needs to do. It's great.