Which Marina and the Diamonds song was released on December 7?
How to Be a Heartbreaker: "How to Be a Heartbreaker" is a song by Welsh recording artist Marina and the Diamonds from the American version of her second studio album "Electra Heart" (2012). Marina and the Diamonds:  Diamandis has described herself as an "indie artist with pop goals" and often analyses components of human behavior in her music.
"How to Be a Heartbreaker"