'The Voice': Carter Rubin's 'Rainbow Connection' Makes Gwen Stefani Break Down

The 15-year-old singer wowed the coaches again in 'The Voice' semifinals.

Carter Rubin is doing his best to make it to The Voice finals!

The 15-year-old crooner took the stage during Monday's live semifinals to showcase his stage presence and jaw-dropping range, with a cover of "Rainbow Connection" from The Muppets Movie, that had coach Gwen Stefani in tears even in rehearsal!

"Blake's mom literally keeps texting me, like, 'I hope your boy gets through!'" Gwen told the young singer, adding that she picked "Rainbow Connection" as a song she sings to her own boys at home. Carter also dedicated the song to his older brother, Jack, who has autism. 

The stunning cover brought the coaches to tears once again, with Gwen breaking down in her chair before standing for an ovation.

"That was flawless," she gushed. "That was God answering my prayers... You're so gifted, you're so intuitive, your heart is full of music. I'm so honored that you picked me and I'm crying and I'm so happy and I love this frickin' show. Congratulations!"

Carter, the youngest remaining contestant, wowed the coaches during the first live shows last week, with a cover of Mariah Carey's "Hero" that left Gwen brushing back tears.

"I'm just so honored to get to know you," she gushed. "You're so talented... and it's so fun to watch you shine and know that you're good at that. And not only good, but like, mind-blowingly good!"

"And just to be here, for America to see, I have tears in my eyes," she added. "Thank you for choosing me. You're so inspiring."

The Voice looks a little different this season amid the COVID-19 pandemic, with safety glass distancing the coaches and team members and separate performance spaces on stage for the Battle and Knockout Rounds. But Stefani noted ahead of the season how excited the coaches were to be back in any capacity, bringing some music and joy into people's lives.

"I think that being able to sit down and watch a show that's so inspiring and will bring inspiration to people, it will definitely bring joy," she noted. "Music is the heartbeat of human beings, so I feel really blessed to be here and to be a part of that and to be able to connect around America on the TV."

"Maybe the reason there's so much talent is that a lot of people are kind of paused and they get to kind of, you know, follow the dream in a way they didn't get to because maybe they're working or they were in school," she added. "I think there's kind of a different kind of group of people this time because of the opportunity that we are all paused in the world right now."

The Voice airs Mondays and Tuesdays at 8 p.m. PT/ET on NBC. See more on this season in the video below -- and check out how to vote for your favorite performer here!