Okay, so there're these wires and pipe sticking out of my ceiling.
After a little Googling (like this), I decided that the pipe was likely part of a long-gone gas lighting system. And I guess because it was up in the ceiling and difficult to fully remove, previous residents of The Ear just decided to incorporate it into their contemporary lighting needs. Hence the little threaded bit on the end, which was holding up the previous light.
Looking up into the hole, I could see why there was no junction box to attach a light to: the pipe was in the way. The wires were coming out of a ribbed metal tube attached to the floor joists and were spliced onto the lamp wire from the old fixture (which I had to cut).
Well, it looked weird, but I figured I could just attach my new light in the same manner as the old one, by screwing my mounting bracket to the old gas line. One problem though:
The gas line stuck out farther than my fixture was deep. Hence the plastered-to-the-ceiling canopy of the previous fixture. I set about looking for a fix, cutting up all manner of round things.