The onscreen sisters didn't give any hints as to which songs they'd be singing, but we've got some guesses. Clearly, the Game of Thrones theme song has to be included. Turner's currently dating DNCE frontman Joe Jonas , so having him hop in the backseat seems like a given. Williams is also apparently a big Ed Sheeran fan (hence his cameo), so brace yourself for a "Shape of You" singalong. We would also not be mad if Jon Snow (Kit Harington) showed up to perform his ode to Ygritte , "Wildling," again.