Game of Thrones - Season 7 - Ed Sheeran - Arya Stark

Sheeran's cameo came about while Arya was traveling through the woods after leaving the Twins, where she had massacred what remained of House Frey. She stumbled upon a group of Lannister soldiers eating around a campfire and having a bit of a singalong before they continued to ride towards where Arya had just come from, planning to investigate what happened.