Emo music is always keeping in the theme of an unhappy or melancholy attitude or being in a situation that would make one so.
I don't actually notice this with panic! at the disco's songs, they always seemed fairly happy to me, when I listened to them it was cos they made me dance. Can someone explain some lyrics that actually make p!atd emo? For example "there's a good reason these tables are numbered honey.." sounds like a confident song to me about this guy kinda coming back at his ex or something like that.

"I'm the new cancer, never looked better, you can't stand it.
Because you say so under your breath.
You're reading lips "When did he get all confident?"

I never thought any of the songs sounded sad! So that, is why, I don't get emo X_X