The Zac Brown Band's newest album, Jekyll + Hyde, is set for release on April 28, and lead singer Brown is warning fans that the group delved into new territory with their latest set of tunes.

“I think you’ve got the best of what people would expect from our other records, and we’ve even gone deeper down the rabbit hole on some songs to make new music and new avenues," Brown tells Country Countdown USA. "We always push the boundaries on the styles we put on a record. On our last record, we had a straight R&B song. We’ve gone further on this album, where we have a Big Band song, kind of a Sinatra-type song; we have a couple songs that have electronic music on them. We’ve got a couple rock songs, maybe a little heavier than what we’ve done. So the title Jekyll & Hyde really covers the breadth of the record.”

Jekyll + Hyde is the band's fourth studio album, but it's the first they recorded when they weren't on the road.

“Over the last seven or eight years, there’s been a violent growth around us, having five kids, the growth of all my businesses, and touring, just figuring out and getting settled in. So now, we had the ability to unplug for a few months," Brown explains. "This time, I feel like this is the most important record we’ve ever made. I wanted to make a new partnership for this record. I think we’ve got a lot to prove. I want to get better every year. That’s the love for it. I want it to translate, and I’m willing to do the hard work to get it there.”

Brown says the song "Dress Blues" was an important inclusion on the 12-track album, even though he didn't write it.

“Every record we do, we do one song we didn’t write," he explains. "This is that song. It was written by Jason Isbell, it was on a record he did 10 years ago, and it floored me. I just wanted to show the world this song, do it our way, and I arranged a version of "Taps" in the middle of the song. I’ve been to military funerals, and when they played "Taps," it just killed me.

"This song is about a young soldier who got blown up by an IED, and he’s going home in his dress blues," Brown continues. "Just the way this song is written, how American it is, is incredible. Jewel sang harmony on that song. There’s a lot to discover on this album, there’s a lot to absorb, so I hope people who love to dig every drop of a song will dig into it.”

Jekyll + Hyde also includes ZBB's current single, "Heavy Is the Head," which landed in the Top 5 on the Billboard Mainstream Rock chart. It's all part of the theme of the album -- expect the unexpected -- which is evident on the album cover, which shows Brown's face with two different-colored eyes.

“We wanted the Jekyll + Hyde thing to be subtle," Brown explains. "We thought about doing the warped face on one side and regular face on the other, but it was too on-the-nose. So we got one of the best rock photographers of all time, Danny Clinch, to shoot the video, and one of his guys came up with the two colored eyes. I’ve had a lot of compliments on it.”

Jekyll + Hyde is available for pre-order on Amazon.

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