I'd love to hear it the way that you perform it, Steve. It sounds really cool.

From my point of view, something happens to a song when it becomes a "standard" that many performers know. Not sure that it is a folk song exactly, but it doesn't need it's author or first performer anymore, and it lives on it's own.

By the time people start cutting the sleeves off, overhauling the engine, tearing out the seats and putting in a bar, or playing it as a polka though, it's definitely a folk song.