In the movie Frozen, Elsa isolates herself from Anna, fearing that she may accidentally kill her little sister. Anna doesn't understand why her loving sister has withdrawn from her life. She invites Elsa to play with her in the song "Do You Want to Build a Snowman?," which is embedded below. It's a hard, tragic scene in the movie.
Similarly heartbreaking is the breakup of the Joker and Harley Quinn from the DC Comics universe. They were a romantic couple, but the Joker couldn't climb out of his own depression enough to keep the relationship going. Harley did her best to encourage him, inviting him to come out of his lair to kill the Batman. YouTube user SydneyAmber sang this pitch-perfect parody of the Frozen song.
-via The Mary Sue