I never thought I'd start something so huge with this!
I'll concede the possibility of a ceiling being a roof under MisterMatt's conditions of beams that act as both - but in a traditional, modern room they are two different things.
While some posters do seem to be struggling with literary devices, it is possible for some devices to simply not be effective as well...
And to add to the thread, though it's technically not a theater related lyric (though it is in We Will Rock You) what's with Freddie Mercury singing "Fried chicken" at the end of One Vision?
Hi, Shirley Temple Pudding.