Kristian Bush recently debuted a brand-new song, "Walk Tall," at the Grand Ole Opry.

The tune, from his upcoming solo album, Southern Gravity, was written for his adolescent son.

"It's not what you do when people are looking that matters; it's what you do when people aren't looking," Bush shared from the Opry stage. "I write songs for a lot of different reasons. This one I wrote because my son just turned 12. I'm pretty proud of him, but it's pretty daunting as a parent to think what would you tell your son; what advice would you give him?"

With lines like, "They say the measure of a man / Is what he does when he's in trouble / When you face the fires of hell / Will you stand or will you stumble? / It ain't the easiest way of life / To push a demon in the night / Can't be scared to pick a fight / Gotta do right," it sounds like Bush is on the right track.

"This song is the beginning of that conversation for me," Bush explains on his website. "The first line is where it all starts. The way we find out what we are all made of is when things go bad. I feel like these lyrics cut to the truth of what we all go through, man and woman alike."

Southern Gravity's debut single, "Trailer Hitch," landed in the Top 20. But even the seasoned performer, who spent several years as one-half of the hit duo Sugarland, admits that he has no idea which songs from Southern Gravity will be successful on the charts.

“When you write a hit song, it’s not a hit song when you write it. It’s just a song. And it’s not even a hit song when you record it, or even when they start playing it on the radio, it’s still not a hit,” he tells The Boot. “Like, two years later, they call you, and they’re like, ‘Hey, Kristian, that was totally a hit.’ And I’m like, ‘What did I eat that day?!’”

One thing is certain, however: Southern Gravity won't be a depressing record.

“I didn’t want to make an album of lament,” Bush says. “That’s a pitfall in many people I’ve seen step away from their acts and then say, ‘I want this to be the sad version of my life.’ I personally love those records, but it’s not the record I wanted to make. I always tell people that it’s so much harder to make a happy song than a sad one.”

Southern Gravity is due in stores on April 7. It is available for pre-order on iTunes, Amazon and Google Play, as well as on KristianBush.com as part of a merch bundle.