Inside Fame, CMT's hit biography series, will return May 22 with the first in-depth profile of country megastars Florida Georgia Line.

The duo of Brian Kelley and Tyler Hubbard catapulted to success in 2013 with Here's to the Good Times, their chart-topping, platinum-certified debut album for Republic Nashville. The project has sold more than 1.7 million copies and netted four consecutive No. 1 singles.

One of the album tracks, "Cruise," became the best-selling digital single in country history with more than 6.9 million digital downloads.

"You gotta thank the songwriting gods for that song," Hubbard says in the documentary. "I mean it's truly, you know, one of those songs that may or may not come around once in a lifetime."

In the new installment of Inside Fame, Florida Georgia Line, who recently scored five CMT Music Awards nominations, speak candidly about the ups and downs on the road to fame and how their passion for music overcame all, driving them to perfect their songwriting and performance skills.

The one-hour special includes never-before-seen childhood videos and the moments that defined them, including Kelley's first performance in Nashville as a child and the tragic helicopter crash that claimed the life of Hubbard's father. Family members, business partners and superstar friends such as Jason Aldean, Luke Bryan, Nelly and Jake Owen weigh in on the duo's fast-rising career.

Kelley and Hubbard also respond to critics who dub their music "bro country."

"We forget about it when we hit the stage and there's 20,000 people screaming every word," Hubbard said.

They also talk about the magic moment when they started working on music together during their early days at Nashville's Belmont University.

"Everything was just better when we were together," Kelley said. "You know, more energy. The songs were better, and it sounded better, and I think it was just more fun."

The new episode of Inside Fame premieres May 22 at 10 p.m. ET/PT.

Visit CMT.com, Floridageorgialine.CMT.com and the CMT Artists App for exclusive outtakes, videos and more. Join the conversation on CMT's official Facebook page and follow @CMT on Twitter using #InsideFame.