John Legend reveals the song he sings to his daughter while changing her diaper

Having an award-winning singer and songwriter as your dad definitely has its perks. 

John Legend and wife Chrissy Tiegen have been doting on their 1-year-old daughter, Luna. The "La La Land" star told Gayle King that being a dad has given his politics a greater purpose, and he's enjoying every single step of first-time parenting. 

But he's at least trying to restrain himself when it comes to nicknames -- as much as he can.

"I call her Luna a lot just because I feel like I don't want to over-nickname her just because I feel like her name is her name, and we want to call her that," he said. "But we call her Luna, Lulu, we'll call her Looney Tunes sometimes. Tunes." 

Legend also revealed -- after some prodding from King -- that he's come up with an original tune for serenading Luna while he's engaged in some unsavory parenting work. 

"My worst and best song, it's all the same," he explained. "It's for when I'm changing her diaper."

Legend then treated King to a performance of the song, which goes: "Somebody's got a stinky booty, her name is Lulu and she made a poopie. Somebody's got a stinky booty, and Daddy's gonna clean it up."