EXCLUSIVE: Hear Danielle Bradbery's Thomas Rhett, Jaren Johnston-Penned Song, 'Hello Summer'
Big Machine Label Group

Danielle Bradbery is holding on to those summer vibes. 

The 21-year-old songstress, who won the season four of The Voice on Blake Shelton's team, has teamed up with ET to debut one of her catchy new songs, "Hello Summer," which will feature on her next album. I Don't Believe We've Met is set for release on Dec. 1. 

"Hello Summer" was co-written by Thomas Rhett, Rhett Akins, The Cadillac Three's Jaren Johnston and Julian Bunetta in a session originally intended for Rhett's Life Changes album. When Rhett decided not to select it for this project, he contacted Bradbery. The duo have stayed close since touring together in 2015, with Rhett serving as a mentor in recent years.  

"He felt like the song could be re-written with female perspective, so I sat down with his dad [Akins] and he re-wrote some of the lyrics to fit my voice," Bradbery says. "Julian agreed to produce it and I'm so proud of how it turned out. It's one of the few I didn't co-write myself, but I feel really speaks to the same emotional theme of the record and pushes the boundaries sonically into new territory for me." 

"We jumped in and cranked that story out really quick and then started another," Johnston tells ET, recalling the session. "I really thought it was gonna be on TR's new record, so I was really surprised when I heard Danielle had cut it." 

"I guess that's what's so great about Nashville and writing country music -- you never know where a good song is gonna find a home," he continues. "I recently heard her version and I love it. What a true talent she is! She killed it." 

The ironic timing of the song's release isn't lost on Bradbery, who joked about the title in an Instagram post of a yellow shirt that reads, "Goodbye Summer." 

"Because we are releasing a song called 'Hello Summer' on the first day of fall," she cracked. 

I Don't Believe We've Met is available for pre-order now.