Sam Breakaway by Kelly Clarkson. It talks about flying, and wanting to make a difference, which is exactly what Sam wants to do. Also he's a closet Kelly Clarkson fan, but I mean who isn't???
Steve: Photograph by Ed Sheeran. All he has left of his love for Peggy is pictures that he probably carries around wherever he can. It just gives him the feels.
Tony: Shoot to Thrill by ACDC. He does everything to impress someone. To be honest, he probably lives on the feeling of thrilling others.
Thor: Rather be by Clean Bandit. When he's with Jane, it doesn't matter to him if it's in Asgard or Earth, as long as she's there he's happy.
