Blake Shelton has been with The Voice since its inception, and while several other stars have rotated through the TV singing competition's big red chairs, the country singer and pop artist Adam Levine have been coaching constants -- and there's a reason for it.

“They love doing the show, and they love the paycheck,” NBC Chairman Robert Greenblatt jokes (quote via ET).

In all seriousness, though, Shelton -- who says his The Voice gig fell into his lap -- and Levine are considered the "series regulars," according to Greenblatt ... and they're not about to go anywhere.

“[Shelton and Levine] are always hugely popular whenever we do testing, and we’ve done a fair amount of that over 11 cycles," Greenblatt explains. "We think they’re the pillars of the show, and then we have this revolving family of Gwen [Stefani], Pharrell [Williams], now Miley [Cyrus] and Alicia [Keys] joining the pack.”

In fact, Levine and Shelton's relationship is part of The Voice's draw: Jennifer Salke, NBC Entertainment president, notes that whenever there are newcomers on the show, it “always stirs up their bromance," while Greenblatt calls the guys' relationship one of the foundations of the show.

“We think the heart of it is those two guys and what they’ve built and their relationship and the surprise of the new people," he says.

And fans of The Voice can rest assured that the bromance between Shelton and Levine will live on. Back in May, the country artist shot down rumors that he was leaving the show, saying, "I don’t plan on going anywhere. I’d like to stay there as long as I can. Of course I’m going to stay there!”

“The moron is coming back, too,” Shelton added of Levine. “It’s going to be a lot of fun.”

Shelton, Levine and company are currently filming Season 11 of The Voice, and Shelton recently revealed that his mentor for the coming season will be "Wind Beneath My Wings" singer Bette Midler. She's excited, albeit a little nervous, about the opportunity.

"I thought, ‘He’s really cute, he’s really funny, he has a tremendous amount of personal charm, and I would like to be in his orbit, so why not?'” Midler confesses, adding, “[H]e’s a tremendous coach … I was a little bit freaked out to have to do this ’cause I thought, ‘What the hell am I gonna tell these kids?’ I’d seen other coaches and their riffing and running, and I’m like, ‘I can’t do that.’”

The Voice returns to NBC on Sept. 19, but fans can get a sneak peek in a special preview episode on Aug. 21, following the closing ceremony of the 2016 Summer Olympics.

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