Thomas Rhett on the Vocal Lessons That Took Him to Brand New Heights on Upcoming Album: 'My Goal for 2021'

Thomas Rhett doesn't ask for much. But before the conclusion of 2021, the country music powerhouse did want one thing.

He wanted to hit a high B note.

"My highest note in my register was an A, and I really wanted to hit a B by the end of 2021," Thomas Rhett, 31, explains in a recent interview with PEOPLE. "And we worked, and we worked, and we worked and she taught me how to not sing from my throat and sing from my stomach."

The 'she' Thomas Rhett speaks of is his current vocal coach Liz, whom the Georgia native and Grammy Award nominee has been busy working with over Facetime for "a couple years now."

"I started implementing [what I was learning] here and there on the road and trying to go for higher notes during soundcheck, just to make sure I wasn't going to sound like I was going through puberty," he says with a laugh during the Zoom conversation. "I started to get really confident with it."

In fact, Thomas Rhett's new vocal skills will soon be heard all over his upcoming album Where We Started, including on the just-released song "Angels."

"That last note that you hear [is] a B," Thomas Rhett says proudly of the poetic ballad he wrote alongside Julian Bunetta, Jaten Dimsdale and Josh Thompson. "And that was my goal for 2021, to hit a B on a record and, and thanks to Liz for teaching me that I could do that."

Indeed, with nearly 10 years of recording under his belt since his debut album It Goes Like This and a slew of chart-topping hits such as "Die a Happy Man," "Country Again" and "Remember You Young" filling his country music resume, Thomas Rhett continues to be one of the genre's hardest working artists continuing to better himself and listen to his gut.

And in doing so, sometimes not everything goes as planned.

In fact, while fans fully expected Thomas Rhett's sixth studio album to be the continuation of last year's Country Again: Side A, the Georgia native soon realized that his muse was leading him in a different direction.

"Obviously, the normal thing to do would have been to come out with Country Again: Side B," Rhett remembers. "But as we started working on that record, I wrote this one song called 'Where We Started' with some good friends of mine Jon Bellion, Jesse Frasure and Ashley Gorley. This song, for some reason, spurred a lot of other songs that kind of followed suit with it. And when we got in the studio and recorded this song, it started becoming not what I thought I wanted Country Again: Side B to be."

So, the father of four decided to pivot, and Where We Started was born. But even he couldn't envision superstar Katy Perry singing with him on it.

"I don't think we were looking for a collaboration on this song," he says of the song that eventually became the album's title track. "Allison Jones over at the label was like, 'Do you care if I send this to Katy Perry's team?'" remembers Thomas Rhett. "And I was like, 'Yeah, but I mean, they're not going to respond, but you can send it."

And within 24 hours, Thomas Rhett had his answer. Perry was all in.

"She really put a lot of time and effort into this vocal and it's one of the best," he says of his collaboration with the superstar. "I mean, she's an incredible singer, but this kind of reminded me of how amazing of a vocalist she is. I just felt like it really came to life."

The new album also includes collaborations with fellow country artists such as Russell Dickerson, Florida Georgia Line's Tyler Hubbard, and Riley Green.

"Riley and I have gotten really close over the last couple years," says Thomas Rhett, who joins vocal forces with Green on "Half of Me." "We've been hunting buddies and have gotten to do some shows together. I wrote a couple songs on his last record and it just kind of felt like it was time for me and Riley to do something together. Me and Riley have actually sung this song a couple times live, and he's just the perfect dude for this song."

Where We Started is out April 1.