“I love three-part harmony but then you add another. Four-part harmony? Even better.”

The Battles stage of The Voice is typically pretty straightforward: Two Artists enter, only one Artist leaves (barring a Steal, of course). But one of the Battles to decide which members of Team Reba would advance to the Knockouts was a little bit different, because 18-year-old country singer Katie O was facing off against not one but three people: the trio 323.

This Battle was all about harmonies, which makes sense because, as one of the members of 323 put it, Coach Reba McEntire “knows harmonies better than anybody.”

“I wanted to find a harmony song that all four of them could sing together,” McEntire said. “I put 323 and Katie O together because Katie O has that real country sound, and 323 could be gospel, could be country. I thought those four voices would blend well together.”

The prospect of having to add a fourth member to their trio, albeit temporarily, was a little daunting for 323. “People think that singing in a group is easier, but it’s a lot harder because it’s all about blending together as a unit,” one member explained. “And for battles, fitting in Katie at the same time was really difficult. Because we already have good dynamics as a trio, but adding that fourth person in, you’ve got to learn how to sing with them, too.”

The song they had to figure out how to sing together was Little River Band’s 1979 hit “Lonesome Loser,” which McEntire said she was especially fond of because the band played at her 50th birthday party.

The Voice Season 26 Team Reba Battle: Katie O vs. 323

Katie O. and 323 perform during Season 26 Episode 11 of The Voice. Photo: Casey Durkin/NBC

Before the performance, McEntire said Katie O’s challenge would be to “really stand out on her own and shine” because she was going up against three people… and that’s what she did. Gwen Stefani said that 323 were “probably my favorite trio I’ve ever seen on the show,” but she was flabbergasted and amazed by Katie O.

“You’re just such an adorable girl but your voice, oh my gosh, your voice is just perfect,” Stefani gushed.

Michael Bublé joked that he felt like the titular “lonesome loser” because he turned his chair for both Katie O and 323 during the Blind Auditions, but neither act chose him as their coach.

“I love three-part harmony but then you add another. Four-part harmony? Even better,” Bublé said.

Snoop Dogg echoed his fellow Coaches. “The three of you always harmonize, but for all four of you to do it? C’mon now,” he said, before eventually telling McEntire that he’d personally give Katie O the win. “Katie O, what surprised me was your voice was probably the strongest. You didn’t try to project it, it just fit in the space like that.”

“Katie O you did a great job,” McEntire told her young singer. After lamenting that both acts couldn’t just advance to the Knockouts together as a quartet, she named Katie O the victor.

“My heart just said go with Katie O. She wasn’t intimidated by the other three people there. She held her own,” McEntire explained. “She stepped up. She didn’t have that in the beginning. She stepped up here.”