'The Voice': Why Did Adam Levine Quit?

Fans were shocked when news broke this morning about The Voice judge Adam Levine not returning for Season 17. Not only is this shocking because Levine — who's been a judged since the popular singing competition started back in 2011 — but because NBC made the announcement two weeks ago on May 10 that the Season 16 judges would all be returning: Adam Levine, Kelly Clarkson, Blake Shelton and John Legend.

Host, Carson Daly, made the announcement official this morning on the Today show saying, "After 16 seasons, Adam Levine our beloved coach and friend has decided to leave The Voice."

"Adam was one of the original coaches that launched the show, winning the competition three times and inspiring many of the artist he worked closely with over the years," he added.

This past season was a bit rocky for the Maroon 5 singer because not only did he make heated headlines, but he looked less than happy at times.

A source close to the singer told Us Weekly, "Adam's decision was [a] difficult one for him. It had nothing to do with backlash.

Another source said that the singer disliked the show for several seasons and wasn't a fan of the format or the fact that America favors country music.

The 40-year-old star came under fire this season when fans thought he played favorites after he defended singer Raegan Strange. After he performed on stage with his fellow judges on May 13, fans wondered how happy he really was being apart of the judges panel because he didn't seem amused on bit.

Not only were fans shocked at the announcement, but so was Shelton.

"Having a hard time wrapping my head around @adamlevine not being at @NBCTheVoice anymore," he tweeted. "After 16 seasons that changed both of our lives. I only found out about this yesterday and it hasn't set in on me yet. Gonna miss working with that idiot."

Shelton and Levine became close friends after the show launched and America fell in love with their frenemy-type-relationship on-air.

Despite his thoughts on America favoring country music, Levine did win three seasons: Season 1 with Javier Colon, Season 5 with Tessanne Chin and Season 9 with Jordan Smith.

So who will fill the spot?

Daly also announced that Shelton's girlfriend Gwen Stefani will judge Season 17. The singer is a returning to the show after judging Season 7 where she and Shelton originally met and flourished their relationship.

The Voice will return to NBC in the fall.