American Idol will start it's final season next year in Jan. Ryan Seacrest revealed all past judges will come back for one last festive moment.
The producers or whoever are in talks with all past judges to see if they would like to return even the judges who spoke out against the show (ellen, mariah, etc). They would like them to come but they haven't figured out what they would like to do if they do come back.
Some of the judges that appeared on the show in its entire run include Simon Cowell, Paula Adbul, Randy Jackson, Jlo, Mariah, Nicki Minaj, Ellen, Harry Connick Jr, Keith Urban and Steven Tyler
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I would laugh so hard if they had Jlo, Mariah and Nicki on the same episode