There isn't, really. Partly truly shocking. Marianne Faithfull. "A Stranger on earth" is rock. "A perfect stranger" they classify as folk. And "Blazing away" they classify as pop. Do they still have all their marbles?
And yes, before someone here gives me a lecture, I know about their older stuff and their folk experiments. But these three albums are the ones that have "Sister Morphine" on them - and the rest also goes in similar directions. That's neither folk nor pop, you poppets.