It's actually a song about bandmates. It was inspired by Liam and Noel Gallagher from Oasis but adapted to not be so specific. The curtain reference is presumably about having to be business partners even when personal relationships have broken down. Like, I hate you, but I'll see you once we hit the stage.
I really, really love this one. As simple as the lyrics are, they're really emotional and earnest and hit their target. It's a spin on the subject of losing someone(presumably suicide) that you don't see alot I guess.
This remains my most anticipated. So excited.