The Voice originally aired back in 2011 and is based on the original show The Voice of Holland. The Voice made itself stand out from other singing reality competitions thanks to its "Blind Audition" process, which involved four judges sitting in chairs with their backs turned toward the performer.

The coaches often enlisted the help of celebrity advisors to better prepare the members of their team. The original coaches for The Voice were Adam Levine, Blake Shelton, Christina Aguilera, and CeeLo Green. Each coach has their own, unique perspective on the artistry of singing, with each of the four coming from very different singing styles and backgrounds.

The Voice has become a huge success thanks to its unique formula and the personalities of the coaches. While the cast of coaches has rotated throughout the show's run, Blake Shelton has been the one constant coach present on The Voice.

Blake Shelton Wasn't Originally Meant To Be On The Voice

Blake Shelton is best known as the coach with the country music background on The Voice but is known to pick a broad range of singers, from the R&B vocal styles of Cam Anthony to the rock coached to country vocals of Cassadee Pope.

Shelton is a beloved judge on The Voice and has brought eight of the vocalists he has mentored to win the competition. Fans may find it hard to believe that it was country legend Reba McEntire that was approached first to appear in the reality competition.

Related: Gwen Stefani Reveals She Kept Her Engagement To Blake Shelton A Secret

McEntire ended up declining the opportunity, indicating that she didn't feel comfortable telling people whether they were cut out to make it in the music business. Reba knew the show was incredibly popular in Holland and even watched tapes of the original show.

It was the tapes themselves that prompted her to decline, with the country singer telling Country Now that she could never tell someone to "go find another job" day in and day out.

Adam Levine And Blake Shelton Were The Last Of The Original Coaches

Adam Levine of Maroon 5 was invited on to be one of the original coaches, with his vocal style likely appealing to singers who fit more of the pop-rock genre. Levine and Shelton are known for their playful and mildly aggressive banter back and forth on The Voice.

Levine lasted as a coach on The Voice for sixteen seasons before eventually calling it quits, having won three of the competition during his time on the show. Despite their fiercely competitive nature, it appears that both Shelton and Levine were close friends during the filming of the show.

Related: Adam Levine's Role In Begin Again Isn't Far Off From His Current Circumstances

Adam Levine announced his departure from the show on his Instagram, with no official reason given for why he was leaving at the time.

Rumors swirled that Shelton may have been the reason why Levine opted to leave the show, but Levine later told Ellen DeGeneres that he just wanted to focus on family.

Levine wasn't the first of the original coaches to leave the show. Christina Aguilera originally appeared in the first three seasons of the show before leaving. She would return to the show for seasons five, eight, and ten before leaving the show for good.

CeeLo Green also appeared during seasons one through three and returned for season five before departing the show as a coach, although he does occasionally appear as a part-time advisor on The Voice.

The Voice has since featured a rotating cast of coaches including Alicia Keys, Shakira, and Pharrell Williams.

Blake Shelton is also departing the show after a long and successful run on the NBC show, saying he has made "lifelong bonds" with people on the show like Carson Daly and, of course, Gwen Stefani.

Shelton also gave a shoutout to all the singers that appeared on The Voice and the fans who watch and support the show.

Some Fans Threaten To Pull Support From The Voice

While The Voice continues to be wildly successful regardless of the changes in coaches throughout the show's run, that may potentially change with the departure of Blake Shelton. Some fans are not taking the news of the departure well, even saying that they will likely stop watching The Voice.

The Voice still has incredible coaches that bring in the views, such as the likes of Ariana Grande, Kelly Clarkson, and John Legend, but none have been present and on-screen as long as Blake Shelton has.

Shelton rapidly became a fan favorite on the show with his laid-back and funny demeanor, and of course, the eight wins he has brought to the show.

Related: The Judges On 'The Voice' Have Revealed A Lot About How The Show Is Really Made

Comments on Shelton's announcement post-show support his decision to leave after a long career on The Voice, while others seem to feel the opposite way; one Instagram user stated, "The end of the voice because Blake is legit the only part of the show worth watching."

Others echoed the same sentiment, saying Blake Shelton is the only reason they watch The Voice, saying the show is now losing its comedian.

The comment section is also filled with "Team Blake Forever" from several users, showing the immense impact he has made during his time on the show.

While reactions to Shelton's departure are mostly sad, he seems optimistic about the future of the show, specifically about younger judges like Ariana Grande who can bring a more youthful crowd to view the series.

Grande and Shelton have developed a relationship throughout their time together on the show, and Shelton seems to support the idea of her becoming a permanent judge in his place, although no replacement judges have been announced yet.