For some reason I've never really been able to figure out, I occasionally rewrite song lyrics. Science-fiction fans call them "filk songs," a term that supposedly arose from a typographical error. Although it does lend one ideas (perhaps an article on "The Filk Process" by Alan Limax?) I've never liked the term very much. It strikes me as self-indulgent.
Or maybe it's just the filk songs themselves that are self-indulgent. Just changing the background of a song from contemporary to futuristic isn't particuarly interesting or amusing. That's not to say one couldn't write an amusing science-fiction parody, but I would hope it would have some point beyond that.
Of course, if the song isn't funny at all, it's not really parody, is it? "Bob Dylan's Dream" was inspired by "Lady Franklin's Lament" and many phrases are the same, but nobody could really call it a parody. [Unlike "Ikea Lament", which was written years after I originally wrote this.]