One might think that The Simpsons have passed all of the milestones possible after nearly 28 seasons, but in just a few short weeks, the iconic animated series, which passed its 600th episode earlier this season, will accomplish yet another first. On Sunday, January 15, The Simpsons will air its first ever one-hour episode, with the network debuting a new video offering fans a first look at this episode, entitled "The Great Phatsby." This video gives us our first glimpse at Keegan-Michael Key's character Jazzy James, while the voice actor takes fans behind-the-scenes of the recording process.

The video, which recently surfaced on the Fox YouTube channel, gives us a first look at Jazzy James, who used to be a popular rapper, before his career was ruined. Now he sells "high-end candles" to make ends meet, as we can see during a brief scene where Jazzy James meets Homer Simpson (Dan Castellaneta), Bart Simpson (Nancy Cartwright) and Montgomery Burns (Harry Shearer). The video also shows how Keegan Michael Key crafted the voice for Jazzy James, teasing that he thought Jazzy's voice would be a bit higher than normal, since he has "tiny dreadlocks." The actor also joked that this character represents the pinnacle of his career, because he finally got to work on The Simpsons.

RELATED: The Simpsons Treehouse of Horror XXXII Brings Back Vincent Price

In the first-ever one-hour episode of The Simpsons, featuring Emmy Award nominee Taraji P. Henson (Empire), Snoop Dogg, Common and RZA as guest voices, Mr. Burns (Harry Shearer) tries to relive his glory days, and crosses paths with a mysterious music mogul. After being conned by him and reduced to bankruptcy, Burns seeks revenge on the music producer with the help of Homer, Bart, rapper Jazzy James (guest voice Keegan-Michael Key) and the mogul's ex-wife, Praline (guest voice Taraji P. Henson), along with Snoop Dogg, Common and RZA (guest-voicing as themselves).

Also in the episode, Lisa (Yeardley Smith) is courted by the richest kid in town, Smithers (Shearer) begins a perilous journey and Marge (Julie Kavner) opens an obscure boutique store in the all-new "The Great Phatsby," special one-hour episode of The Simpsons, airing Sunday, Jan. 15 (8:00-9:00 PM ET/PT) on Fox. The Simpsons continues to strike a chord with viewers for irreverently poking fun at anything and everything. As the longest-running scripted series in television history, The Simpsons has become one of the most consistently groundbreaking, innovative and recognizable entertainment franchises throughout the world. With its subversive humor and delightful wit, the series has made an indelible imprint on American pop culture, and its family members - Homer (Dan Castellaneta), Marge (Julie Kavner), Bart (Nancy Cartwright), Lisa (Yeardley Smith) and Maggie - are television icons.

The series has won 32 Emmy Awards, 34 Annie Awards and a 2016 People's Choice Award. It was the first animated series to win a Peabody Award, and was nominated for an Academy Award in 2012 for the theatrical short The Longest Daycare. The Simpsons Movie was a hit feature film, the mega-attraction The Simpsons Ride at Universal Studios has received historic expansion updates with the addition of "Springfield," and the show was honored with a Star on The Hollywood Walk of Fame in 2000. It has been named the "Best Show of the 20th Century" by Time magazine, and called the "Greatest American Sitcom" by Entertainment Weekly in 2013. The series recently was nominated for a 2016 Emmy Award in the category of Outstanding Animated Program, and Fox renewed the series through Season 30. This renewal takes the long-running animated series to 669 episodes, the largest number of episodes for any scripted television show ever, breaking the record previously set by Gunsmoke (635). Take a look at this new video to get a sneak peek at The Simpsons' first ever one-hour episode, "The Great Phatsby."