For me, I think it should be either Highway Unicorn, or maybe Electric Chapel - both songs sort of set the mood for what the night will be, and have big instrumentals.
Church bells. I'm of course talking about Marry The Night. That's how Gaga described the idea behind the song on her MTV special. People would go absolutely apeshit.
Marry The Night can either be the opening/closing. I hope it is the opening. I want Heavy Metal Lover to be the closing. Imagine how amazing it will be dancing to that song at the end
'Marry The Night'. A personal song which encapsulates some of the message on 'BTW'. Club-banger which slowly builds up. Will get everyone pumped up. Imagine the audience chanting the lyrics. Perfect.
I wouldn't mind Marry the Night, since it is a dancing song. And those church bells would be perfect. I only want Hair on piano and I want You and I to be a beautiful piano rendition like she used to do, not the ****** album version.