The new season of “American Idol” premieres tonight on Fox and with it, the debut of three new judges, Mariah Carey, Nicki Minaj and Keith Urban.

The trio join Randy Jackson, the only judge who has been with the show since its 2002 launch. Here’s what we expect from each of the judges. Though their roles will morph as the season plays out, we have a pretty good idea how each will position him- or herself.

*Mariah Carey:
Look for Mimi to put aside the diva-tude and step into the role of earth mother. No, she’s not going to go all hippie on us, but look for the mom of Moroccan and Monroe to show how kind and compassionate she can be as she treats all of the contestants with a little gentle tough love.  As the panel’s biggest superstar and biggest voice, expect her to offer the most valid critiques of the contestants’ voices, especially for the singers who exhibit anywhere near her tremendous range. But pity the misguided contestant who thinks he/she can impress Ms. Carey by trying to take on one of her songs and hit her calling-all-dogs high notes.

*Nicki Minaj: Minaj has the finest line to walk: she’s doing this for the money and the exposure, but she can’t abandon whatever perceived edge she still has (not that some profane mixtape won’t cure that). Expect her to celebrate the oddballs, the misfits that the other judges may not initially embrace. She’s also the judge most likely to take in the whole package, as opposed to just the vocal performance, since she is such a visual artist.

*Keith Urban:
  Urban has the most to gain here. A superstar in the country world, he’s best known to the rest of the world as Nicole Kidman’s husband. If he plays this right, he could have the same kind of mainstream breakthrough as Blake Shelton from “The Voice.”  Urban will be unfailingly kind, but he will be firm and direct in his critiques. He’ll look for overall musicality, given his excellent guitar chops and songwriting ability, and a feel for someone’s authenticity. He’s talked about wanting to show the contestants how to strip down to their core, so look for him to stress to contestants to pack up any bells and whistles and concentrate on the basics. Urban was a judge last year on the Australian version of ‘The Voice,” so also look for him to try to mentor the contestants just as much as he judges them.

Who do you think will be the best judge?