Some artists today speaks up their pain through a song. Sometimes, when someone hurt them like family member, past relationships or even affairs, they just take their pens and put in on a song.
Songs below are heartbreaking songs intended to address to certain people.

Justin Timberlake- Cry Me a River
It was believed that the song is intended for his ex-girlfriend Britney Spears. Even the video was intended to expose what Britney had done. Although it's not yet clear what really happened about their breakup.

Miley Cyrus- Wrecking Ball
Many assumed the song was for her ex, Liam Hemsworth. However, the song was recorded even before they announced their break-up. Well, this song is on the list anyway.

Dixie Chicks- Not Ready to Make Nice
This song isn't about past relationship, rather, for the former US President George Bush, Jr. When Natalie Maines commented something negative about the then President, she received many criticisms and blasts she believed from the ruler. So they wrote it on a song and became a US hit.

Eminem- Cleaning Out My Closet
Eminem may have been abused by her mom as obvious in this song.

P!nk- Family Portrait
Pink may only wanted a happy family, as they eventually fell apart as written in this song. It's like the song was addressed to her father. 

Lindsay Lohan- Confessions of a Broken Heart
Another artist who faced family problem. This song was addressed to her parents.

Taylor Swift- Dear John
Many believed the song was written for her ex-boyfriend John Mayer.

Alanis Morissette- You Oughta Know
The song was written for her ex-boyfriend who's an actor, but I'm not sure who is it. 

Adele- Rolling in the Deep
Another song for an ex-boyfriend. Actually, the entire album "21" is about her ex.