What inspired the dream? Don't know. Flame Fortune, who was actually murdered a few years after I knew her, was talked about as Australia's answer to Madonna for about two minutes, although she was not even Australian, so go figure. I was thinking about Flame yesterday or the day before. Also, I think I read a quick overview/review of Warren Beatty's Dick Tracy film on its 30th anniversary - which Madonna is in - but I feel like I read that after the dream, who knows.
By the way the dream was not of her murder, but of seeing her in a video for one of her very early songs, like 'Holiday' or similar, in a gritty, rained-on bluestone (?) street, and being reminded, via a voiceover or a comment from a random in the room, that she was dead within a year. Nasty.