Song help!

Okay, in the episode "You Can't Always Get What You Want" when Jude is forced to go to to Shay's concert and Shay sings a song for her, what is the song? I really like it but can't find the name of it or if it is even a real song. Can someone help?

"I think the worlds going to end bloody But it doesn't mean we shouldn't fight We do have choices"