But in the case of Omar Jose Cardona from Team Legend, sometimes singing can be so good it prompts playful roasting instead of compliments.
“I'm pretty sure he was lip-syncing on that one," Stefani joked, after Cardona nearly blew the roof off the studio with his high belting on Celine Dion's "My Heart Will Go On."
"There’s no way that was real. We’re moved to laughter because we can’t take it seriously that you can sing that good."
Stefani's hubby and fellow coach Shelton agreed.
"All across America right now, old men are getting up off their easy chair and picking up their toupee," he said.
Legend said Cardona can do anything: "I feel like as a coach I just try to dream up what challenge I can issue to Omar, because Omar can do it."
Here's who else raised the bar in the semifinals.
Camila Cabello says Morgan Myles is 'The Voice' after tear-jerking tribute
There wasn't a dry eye in the house by the end of the episode, which closed out with a stunning performance from Team Camila's Morgan Myles. The 35-year-old country crooner teared up as she sang an elegant cover of Lady Gaga's "Always Remember Us This Way" dedicated to her cousin who died from brain cancer at 33.
"When you were up there just now, there was just something so magical about it," Cabello said. "This show is called ‘The Voice,’ and I feel like you are that in a way. Your voice has truth and grit."
Myles left Stefani speechless.
"It’s hard to find words," she said. "There’s just something that has been honed in a way."
Blake Shelton gives 'good dude' stamp of approval to bodie
Shelton has been coaching contestants on "The Voice" for a long time — and he says he knows a good dude when he sees one.
He says his team member bodie fits that bill.
"Dude, I think you’re going to the finale," Shelton said after the 29-year-old's energetic cover of "Without Me" by Halsey. "We all know that you have this absurd amount of talent and this knowledge of music and what you want to do and how you want to put it together, but I want America to know what’s in this guy's heart, and this is a good dude standing up there."
Team John Legend singer has every coach wanting to attend her concert
Is this "The Voice" or a Kim Cruse concert?
That's the question the 30-year-old constant from Team Legend left coaches wondering, after her soaring take on the jazz standard "Summertime" from the George Gershwin opera "Porgy and Bess."
"I definitely want to go to a Kim Cruse concert," Cabello said "The nation loves you. You are magical."
Legend agreed, saying he wants "to go to a Kim Cruse concert too."
"Divine was the word that came to my head," he said. "It was just a masterclass in how you perform a song that’s been performed a jillion times."
Shelton also appreciated her simple staging.
"For the first time in over a decade, I saw some choreography on stage that I can actually do," he joked. "Finally. I could have been one of the dancers tonight."
To vote for any of the singers featured in the top 8, visit The Voice Official App or NBC.com/VoiceVote.
This article originally appeared on USA TODAY: 'The Voice': Gwen Stefani accuses singer of lip syncing to Celine Dion