John Legend is loving his new role as a dad.
The 37-year-old musician and wife Chrissy Teigen welcomed daughter Luna in April, and it's safe to say life has completely changed for the superstar couple. ET caught up with Legend on Tuesday to chat about his program to end mass incarceration, #FREEAMERICA, and his hit show, Underground, when he gave us an update on his family. Legend was a panelist at the Television Academy's "Unlock Your Potential" event, which examined how television tells the story of the American criminal justice system and its impact on the population.
"You never know what it's going to feel like until it happens, but you know, I was excited," Legend tells ET's Kevin Frazier about having a child. "And this wasn't an accident, this was something that we have been working on and [we've been] trying to have a family for a while."
WATCH: Chrissy Teigen and John Legend Bring Baby Luna to Cheer on the Los Angeles Dodgers
"Knowing that it was so important to us, I was pretty excited from the beginning, but once she came out and she was actually a real thing that we could hug and love and see her develop, it's pretty powerful," he adds. "It is a pretty powerful emotion to see the product of your love right there in front of you."
He admits that the dynamic between himself and his supermodel wife has changed as well.
"Well, it's all-encompassing too -- it's, you have to spend every moment even when you are not with [Luna] thinking about who is with them, and what's happening with them, and making sure that everything is, you know, comfortable for them," he explains. "Being married is not the same as having a kid because being married to another adult who can take care of themselves to a degree is different than having a kid that is completely dependent on you. So, it definitely makes you realize a heightened level of responsibility and it makes you realize that there is a lot of work to be doing, and you realize what your work is for."
Legend certainly has plenty of work these days. The "Ordinary People" singer is moving into a new house, finishing his new album, and will eventually start touring. His plan is to not be apart from his family for more than a week at a time.
Not surprisingly, Luna has already made her mark on Legend's music.
"You will see in here the influence on the next album of me having a kid," he says. "I couldn't help but write about her. I was writing songs about her before she was born, just because I was so inspired [about] just the fact that Chrissy got pregnant. So, I think it inspired one of the most beautiful songs in the album, and so hopefully that people will love it."
"The subject matter is you just thinking about what it means to have a child, and when you bring a child into this world -- which you know, there are a lot of great things about this world, but there are a lot of, you know, things that concern you about this world too -- and you want them to live the best lives that they can live," he teases about the song. "You want them to take all the good things that you can teach them and be the best person that they can be. But it's always going to be a challenge, and the song is really questioning, like, 'What are you going to be like when you grow up? Whether, you know, you look like me or look like mom, will you take on these traits or those traits?' And you know, really thinking about the world that she is coming into and how she will move in that world."
It's no secret that Legend is active when it comes to social issues, and aside from his work on #FREEAMERICA, he is also executive producing the Civil War drama Underground. The WGN series centers on a group of slaves planning a daring 600-mile escape from a Georgia plantation using the Underground Railroad.
"I studied African American studies and I read these slave narratives and the escape narratives of people that were able to escape slavery, and always found those stories intriguing and powerful and inspiring," Legend says. "And when I saw the treatment of it in the script, I thought this was the perfect show for us to do and so we did it."
"If you think about it, it's kind of a wonder why this subject has never really been addressed in this thorough of a way before," he adds. "If you look at what happened with Underground Railroad there is so much action. There is so much intrigue, there is so much of historical importance."
WATCH: John Legend Kisses Chrissy Teigen's Boob in PDA-Packed Snapchat
ET caught up with 30-year-old Teigen in May, when she also candidly chatted about how her and Legend's lives have changed since welcoming their first child together.