Music does have that ability to reach through the wall of the heart and squeeze, does t it? You do love Florence! I guess songs tend to mire explicitly break the fourth wall as the musician always directly speaks to an audience - the stage is more present and overtly there, as opposed to film or rext where you look as a voyeur onto a scene. It's more jarring when actors or characters break the fourth wall as it's unconventional.
I wonder if there is much theatre that breaks the fourth wall. The stage is there. I've only seen a few shows in proper theatres, they were very much not big on breaking down that wall. Its a shame that so much theatre is musical - I prefer the dramatic.