The singer and wife Heigl adopted their daughter Naleigh from Korea in September 2009, an experience which he confessed has changed his life as well as his music career.
"[As] I was writing for [my new] album, we adopted a little baby girl and then I had everything under the sun to write about. I love being a dad and writing about that," he told HitFix.com.
However, he expressed disappointment that the 2-year-old was not impressed by a lullaby he wrote in her honour entitled 'Naleigh Moon', saying: "Right now, my pretty song gets beat out by the Wiggles and Yo Gabba Gabba."
He also insisted that he and Heigl are ready to give their daughter a sibling.
"We're definitely going to give Naleigh a little friend. She needs a buddy," he added.
Heigl previously admitted that she never expected Kelley to be a good father.