Heartsong is a kind and gentle unicorn from Manehattan. She moved to Ponyville for reasons currently unknown. All in all, Heartsong is a shy, but very kind pony who would do anything for her friends. She lives in a small cottage just down the road from Carousel Boutique.
Heartsong comes from a wealthy, fairly famous family. She has 9 siblings, all of whom are mildly to majorly successful and famous. One of her siblings is the famous "Pony of Pop", Sapphire Shores. Her relationship with her sister is questionable, to say the least.
Heartsong's cutie mark spans across her entire body, even appearing on her face! She learned at a young age that she cannot hold back her emotions. Instead, she fills with song, putting words to whatever she feels deep inside. It's a gift and a curse, really. She's able to do something that very few ponies can: truly express what she really feels. On the other hand, she also fills with song when she's really angry, or upset, and can sometimes say hurtful things to other ponies. She really has no control over what spills out of her at any given time. It could be why she's had a hard time making friends in the past.
Though her relationships in Manehattan are unknown, it's well known among the folks of Ponyville that she's in a relationship with Qwerty Keys, and is very happy with him. She counts Juniper Kick and SweetKiss among her two closest friends.