What if one day, out of nowhere, a music superstar decided to perform a concert right where you were standing?

Fans at the Rock and Roll Hall of Fame on Saturday now know what that feels like, after rock legend John Mellencamp surprised visitors outside the museum with an impromptu concert.

Mellencamp played a set with the group "Pop Fiction," to the delight of the crowd. He even used one of his old guitars housed at the Rock Hall.

Mellencamp was inducted into the Rock and Roll Hall of Fame in 2008. He is in town to perform at the Canfield Fair on Sunday.