The era is unknown, but the title is indeed real it was reworked by Mark Ronson to be released posthumously but never made the cut. The snippet is CLEARLY fake, at least to me and most people i come in contact with. The lyrics make absolutely no sense at all which is a sign that it is consisted of acapellas of other songs edited together. You can hear distortion near the end from where its edited. The beatbox in the intro is offbeat as well, it just doesn't even really sound like an mj song. The watermark which says "this is the property of legend80" has appeared in other fake snippets -
also not sure if you know about the story but the guy who posted the snippet contacted these people to set up a crowd funding and announced it, hyped it up, then.... cancelled it out of nowhere lol.