Rob Kim / Getty Images North America 1 / 11
Rob Kim / Getty Images North America 1 / 11

Kelly Clarkson has mined her past and her troubled relationship with her father -- or lack thereof -- for musical inspiration.

On Feb. 29, the singer opened up during a radio interview with Ryan Seacrest about her single "Piece by Piece," which is inspired by her husband, Brandon Blackstock, and their daughter, River Rose, and also by her own dad, Stephen Clarkson.

"Watching my husband love on his daughter all the time, you know, go to her events and just be there and, like, be present is hard to watch but beautiful to watch," said the "American Idol" alum, via Us Weekly. "I know that my kids are going to have that."

Starting a family of her own completely changed her perspective of her relationship with her absentee dad, says the 33 year old.

"I don't even think I understood the gravity of [my relationship with my father] until I was pregnant with [River Rose]," she told Seacrest. "I was like, 'I cannot imagine not seeing this kid to his or her full potential and just seeing what she's going to do, what she's going to be like.' … I don't think I knew how much that affected me until writing ['Piece By Piece']. I definitely didn't know how it would affect me like it does when I sing it live because that's not fun. It's awesome, but it's kind of sad that so many relate to this song."

The song is so emotional for Kelly, in fact, that she was moved to spontaneously announce that she's expecting her second child, a boy, after she broke down in tears while performing it during a concert in Los Angeles in August.

"I'm totally pregnant again," she revealed at the time.

"That was not planned. I just didn't want you to think I was crazy," she added. "Honestly I'm just hormonal today. Nothing's wrong I'm OK. I haven't vomited yet!"

In "Piece by Piece," Kelly sings of her father: "And all I remember is your back/Walking towards the airport leaving us all in your past/I traveled 1500 miles to see you/Begged you to want me/But you didn't want to."

She concludes the song by singing of her hubby and their baby girl, "She will never have to wonder her worth/Because unlike you I'm gonna put her first/He'll never walk away/He'll never break her heart/He'll take care of things/He'll love her/Piece by piece/He restored my faith/That a man can be kind/And a father should be great."

In spite of the pain, the singer says she's "not angry" about her dad anymore.

"I'm 33 years old, I'm a grown woman," she said during her interview with Seacrest. "But it's more of that thing where you can try your hardest to salvage relationships -- and I did -- but at the end of the day, if you keep getting hurt by someone because they just don't know how to properly love people, it's just not worth it," she concluded. "It's not worth the strain in your heart and it starts to bleed into your other relationships and it becomes super dysfunctional."