Thomas Rhett Makes Fans Swoon All Over Again with 'Life Changes' Track 'Sweetheart': Premiere

If you've paid any attention to Thomas Rhett's music since he released his first single "Something To Do With My Hands" in 2012, you are fully aware that he is a man of no boundaries. While the 27-year-old singer remains country at his core, he's infused pop, R&B and even a sprinkle of hip-hop into his material -- and with the release of his third LP Life Changes coming Friday (Sept. 8), he's adding more layers to his catalogue, including a little '50s doo-wop.

Just one day before Life Changes is released, Rhett unveils a track called "Sweetheart," premiering on Billboard below. Although it's certainly tough to beat Rhett's swoon-worthy ballad "Die a Happy Man," "Sweetheart" is definitely one of his most romantic songs because of how he nailed the classically tender tone of an earlier time.

"I really wanted to write a simple love song," Rhett tells Billboard. "A lot of times as songwriters, we try to overanalyze every lyric, but what the '50s did so well -- when you listen to Sinatra songs, why do we like them so much? It's because it's just easy to digest and it makes you feel amazing. We wanted to write a song like that, so that's where 'Sweetheart' was born."

Rhett co-wrote the croon with his dad Rhett Akins, Joe London and Sean Douglas -- "love songs are kind of our thing," he says with a smile -- during a writing trip in Charleston, which he says was one of those magical sessions where the chorus just kind of fell out and the song was written in no time. And while they were all impressed by how quickly it came together, Rhett got the most important approval of all upon playing it for others.

"It's my wife's favorite song on the record, so that's one of the reasons we put it on this record," he says. "That, and I just love the way it makes me feel."

With a dreamy melody and sweet lyrics like "'Cause you're all that I adore/ You're the one my heart beats for," it's not surprising that Rhett's wife of five years, Lauren, would favor this tune over the other 13 on Life Changes. But while it's no secret that she has been the subject of all his love songs over the years, the opening line of "Sweetheart" finds Rhett acknowledging that he hasn't expressed his love enough lately: "Woke up this morning to your sleepy smile/ Realized I haven't told you in a while/ That you're my life, you're my dream, you're the reason for every song I sing."

How could the guy behind "Die a Happy Man" think he doesn't tell his wife "I love you" enough? Well, as if Rhett hasn't made you fall in love with him already, his explanation for that line will definitely do it.

"I think any couple, whether they're dating or married, can get into these like rut seasons where it's kind of like, 'I've been working too hard' or 'We haven't really talked a whole lot this week,' and that's kind of where that verse was inspired," he explains. "You wake up and you look at that person -- for me, Lauren -- like, 'Why do I not tell you this a jillion times a day?' I think every girl would love to hear that."

Check out "Sweetheart" below and get your copy of Life Changes on Sept. 8.