The modern songs heard on the player piano in the Mariposa Saloon and Hotel are the idea of writer, producer, and director Jonathan Nolan. Nolan and composer Ramin Djawadi explained that the covers are to remind people that the world is a theme park, and that everything is scripted. The songs are chosen by Nolan.
Man in Black:
Aw, yeah, cue the waterworks. About time you realized the futility of your situation.
Dolores Abernathy: I'm not crying for myself. I'm crying for you. They say that great beasts once roamed this world. As big as mountains. Yet all that's left of them is bone and amber...